GB2555893A

GB2555893A - An injector insert for a t-joint

Info

Publication number: GB2555893A
Application number: GB1711334.1A
Authority: GB
Inventors: William Madigan Terence
Original assignee: Systemlink Aquaeco Ltd
Current assignee: Systemlink Aquaeco Ltd
Priority date: 2016-07-14
Filing date: 2017-07-14
Publication date: 2018-05-16
Also published as: GB2555893A8; GB201612268D0; IE20170146A1; GB2552215A; GB201711334D0

Abstract

An injector insert 1 for adapting a standard T-joint 7 comprises an elongate length of pipe 3 having an external diameter DE less than the internal diameter DI of the T-joint 7. The pipe 3 has a collar 5 at one end dimensioned to engage and rest on an internal annular seat 9 of the T-joint 7. The external diameter DE of the injector insert may be between 0.3 to 0.8 times, preferably 0.6 - 0.75 times, the internal diameter DI of the T-joint. The collar 5 may be frusto-conical. The other end 13 of the pipe 3 may be open or closed and may have exhaust apertures 11. The injector insert 1 can be used to convert a standard T-joint into a flange capable of performing the function of a plethora of other flanges. The injector insert 1 can also be used to create an injector Tee with a standard T-joint. This reduces the complexity and expense of many existing systems and substantially reduces the inventory required by tradesmen and retailers. Hot water installations and methods using the injector T-joint are disclosed.

Description

(71) Applicant(s):

Systemlink Aquaeco Limited

Unit 1 Greenhills Business Park, Greenhills Road,

Tallaght D24, Dublin, Ireland (72) Inventor(s):

Terence William Madigan (56) Documents Cited:

GB 1581724 A1 GB 0859962 A

EP 2711443 A EP 2592191 A2

WO 1999/031441 A1 US 0971934 A1 KR1020110101295

Shotter, 2013, lnjector-tee.co.uk, [online]. Available from: www.injector-tee.co.uk/end%20feed.html [Accessed 21 December 2017]

Richard and Mary Torrens and Family, March 22 2016, [online]. Available at: www.torrens.org.uk/HowTo/ Injector/ [Accessed 21 December 2017].

(74) Agent and/or Address for Service:

O'Connor Intellectual Property Limited

Suite 207, Q House, Furze Road, Sandyford, Dublin,

Ireland, D18 FR58, United Kingdom (58) Field of Search:

INT CL B01F, F04F, F16L, F22B, F24D Other: EPODOC, WPI, Patent Fulltext, Internet (54) Title of the Invention: An injector insert for a t-joint

Abstract Title: Injector insert for adapting a standard T-joint (57) An injector insert 1 for adapting a standard T-joint 7 comprises an elongate length of pipe 3 having an external diameter D_E less than the internal diameter Di of the T-joint 7. The pipe 3 has a collar 5 at one end dimensioned to engage and rest on an internal annular seat 9 of the T-joint 7. The external diameter D_E of the injector insert may be between 0.3 to 0.8 times, preferably 0.6 - 0.75 times, the internal diameter Di of the T-joint. The collar 5 may be frusto-conical. The other end 13 of the pipe 3 may be open or closed and may have exhaust apertures 11. The injector insert 1 can be used to convert a standard T-joint into a flange capable of performing the function of a plethora of other flanges. The injector insert 1 can also be used to create an injector Tee with a standard T-joint. This reduces the complexity and expense of many existing systems and substantially reduces the inventory required by tradesmen and retailers. Hot water installations and methods using the injector T-joint are disclosed.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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- 1 “An injector insert for a T-joint”

Introduction

This invention relates to an injector insert for a T-joint, an injector Tee, household hot water installations incorporating the injector insert and methods of incorporating the injector insert in household hot water installations.

A common problem experienced by plumbers, plumbing contractors and plumbing suppliers is the large volumes of stock that they each must hold at any given time. This is necessary in order to ensure that they have the correct equipment at hand so that they can complete a given job.

For example, if a plumber is required to retrofit a pumped shower in a vented hot water installation, it will be necessary for them to fit an appropriate flange to the hot water cylinder in order to prevent suction of water and air through the vent pipe into the pump. If the hot water cylinder is provided with a female coupling, it will be necessary for the plumber to have one of a Warix flange, a Techflow flange and a Surrey flange with a complementary male coupling that can be connected up to the hot water cylinder. Alternatively, if the hot water cylinder is provided with a male coupling, it will be necessary for the plumber to have one of a Salamander flange and a York flange with a complementary female coupling that can be connected up to the hot water cylinder.

Similarly, if a plumber is required to connect up a secondary return system in a hot water installation in order to ensure that hot water is available practically instantaneously at a hot water outlet, and there is no pre-existing connection on the hot water cylinder, the plumber must provide an Essex flange to connect up the secondary return pipe to the hot water cylinder. If the plumber is required to combine two flows into a single flow, they must typically provide an appropriate injector Tee, and if the plumber is required to connect up a secondary heat source to a hot water cylinder, various equipment including one or more injector Tees and/or mixing valves must be provided in order to ensure appropriate and safe operation of the hot water installation.

-2In order to have the appropriate equipment at hand so that they can carry out any of the above or other jobs, the plumber must carry a large inventory in their van. As well as being expensive and taking up valuable room in the van, this may make the van a target for unscrupulous criminals. If the plumber does not carry the equipment in their van, they will have to purchase the appropriate equipment from a plumbing suppliers before they can complete the job and they may have to stop work mid-way through a job in order to go to the plumbing suppliers and purchase the required piece of equipment. This increases the time taken to complete the job, decreases the profitability of the job and results in a loss of earnings on account of other work that could have been done in that time. Correspondingly, the plumbing suppliers themselves must stock all of the different flanges and equipment in their premises to ensure that they have the necessary equipment resulting in a large inventory in their premises that is expensive, space consuming, and a drain on resources.

In addition to the foregoing, the above-identified equipment is relatively expensive to purchase and this increases the overall cost of the job to the end customer and/or decreases the profit margin for the plumber installing the equipment.

Various disparate types of fittings and injector inserts are available on the market however heretofore none of the existing offerings has addressed the problems mentioned above. PCT Patent Application Publication No. WO99/31441 in the name of Jandy Industries Inc. discloses a venturi apparatus for flow control in a heating system. Korean Patent Application Publication No. KR1020110101295 in the name of LG Electronics discloses an ejector. European Patent Application Publication No. EP2711443 in the name of Samsung Corning Precision Materials discloses a gas injector.

It is an object of the present invention to provide a solution that overcomes at least one or more of the above-identified problems. More specifically, it is an object of the present invention to provide a solution that is more cost effective than many of the existing offerings, that decreases the amount of inventory that must be held by a plumber, plumbing contractor or a plumbing supplier, and that provides a useful alternative to the existing offerings.

- 3Statements of Invention

According to the invention there is provided an injector insert for adapting a standard Tjoint, the injector insert comprising an elongate length of pipe having an external diameter less than the internal diameter of the T-joint, the pipe having a collar at one end thereof dimensioned to engage and rest on an internal annular seat of the T-joint.

By having such an injector insert, any standard T-joint with a male coupling can be converted into a Warix, Techflow or Surrey flange and any standard T-joint with a female coupling can be converted into a Salamander or a York flange. Similarly, a standard Tjoint can be converted into either an Essex flange or an injector Tee. This is highly advantageous as the injector insert will reduce significantly the inventory that must be carried by a plumber and/or a plumbing supplier as they will almost certainly already carry both types of T-joint as a matter of course. By adding the injector insert to their inventory, several additional components can be omitted from their inventory.

Furthermore, at current rates, the injector insert will significantly reduce the cost of the components required to carry out a job as the injector insert and the T-joint will be significantly less expensive than many of the existing offerings. In addition to the foregoing, the injector insert will also in many cases reduce the expense and the time taken to complete a particular job. This is due to the fact that in some cases it may be possible to obviate the need to remove existing connections to a hot water cylinder that have become bonded to the cylinder over time and that may be very difficult to remove. In other cases, it may be possible to avoid having to install additional equipment such as a mixing valve in a secondary heat supply system.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the external diameter of the injector insert is less than or equal to 0.8 times the internal diameter of the T-joint. This is seen as useful as this will ensure that there is sufficient room for the water to flow to the lateral port past the injector insert pipe.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the external diameter of the injector insert is less than or equal

-4to 0.75 times the internal diameter of the T-joint. This is seen as a preferred embodiment as the pipe will be sufficiently wide to allow flow of liquid through the pipe while at the same time providing sufficient room for water to pass by the pipe to the lateral port of the

T-joint.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the external diameter of the injector insert is less than or equal to 0.70 times the internal diameter of the T-joint. This is seen as a useful range for Tjoints having an internal diameter of less than 0.0254 m (1.0 inches).

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the external diameter of the injector insert is greater than 0.3 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the external diameter of the injector insert is greater than 0.5 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the external diameter of the injector insert is greater than 0.6 times the internal diameter of the T-joint. This is seen as a preferred embodiment as this will provide sufficient room for liquid to pass through the pipe of the injector insert and through the T-joint when the injector insert is installed in the T-joint.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the other end of the pipe is open. In some cases, the injector insert will be used to draw hot water from a hot water cylinder, deliver cold water into a hot water cylinder or will be used to create an injector Tee. In those cases, it is envisaged that an open end will be advantageous as it will promote the desired flow of fluid through the injector insert.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the other end of the pipe is closed and in which there is provided an exhaust aperture in a side wall of the pipe adjacent to the closed end. In

- 5some cases, the injector insert will be used to deliver hot water into a hot water cylinder and in those cases, in order to avoid disrupting the orderly stratification of the water in the hot water cylinder to a substantial degree and in order to derive the most benefit from the hot water being delivered into the hot water cylinder, a closed end of the pipe with an exhaust aperture will promote the most advantageous delivery and storage of hot water in the hot water cylinder.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which there are provided a plurality of exhaust apertures aligned longitudinally in the side wall of the pipe adjacent to the closed end.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which there are provided a plurality of exhaust apertures in the side wall of the pipe adjacent to the closed end, circumferentially spaced around the pipe. This is seen as a particularly preferred embodiment of the present invention. By having a plurality of apertures spaced circumferentially around the pipe, the water entering the hot water cylinder will be evenly distributed in that level of water in the tank thereby promoting the most efficient storage of hot water in the hot water cylinder.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the plurality of apertures circumferentially spaced around the pipe are evenly spaced around the pipe.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the collar is frusto-conically shaped, splaying outwardly towards the open end. This is seen as a particularly useful embodiment of the present invention. By having a collar that is frusto-conically shaped, the collar will act to self-centre the injector insert in the T-joint when it is inserted into one longitudinal port of the T-joint. In this way, the injector insert will not have a tendency to be angled towards the lateral port of the T-joint and potentially blocking or impeding the flow of liquid through the lateral port.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the collar is provided with an annular flange extending

-6outwardly therefrom at its outermost end. This is also seen as a particularly useful embodiment of the present invention as the annular flange will provide an abutment surface for a conduit inserted into the longitudinal port behind the injector insert. This will further help to align the injector insert in the T-joint, ensuring that it doesn’t act to block or impede the lateral port and will provide a good connection between the conduit and the injector insert.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the pipe has a circumferential weakened section intermediate its ends. By having a circumferential weakened section intermediate its ends, the pipe can be shortened to the desired length or converted from a closed-ended pipe to an open-ended pipe by snapping off the end-most part of the pipe. Indeed, a plurality of these weakened sections may be provided along the length of the pipe to provide greater adjustability. These weakened sections may be provided by one or more striations on the surface of the pipe.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the pipe has an external diameter of the order of between 0.0127m (½ inch) and 0.0203m (0.8 inch) and the collar has a maximum diameter of greater than 0.0254m (1 inch).

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the pipe has an external diameter of the order of between 0.009m (¾ inch) and 0.015m (³/₅ inch) and the collar has a maximum diameter of greater than 0.01905m (¾ inch).

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the pipe has an external diameter of the order of between 0.014m and 0.022m and the collar has a maximum diameter of greater than 0.028m.

In one embodiment of the invention there is provided an injector insert for adapting a standard T-joint in which the pipe has an external diameter of the order of between 0.011m and 0.018m and the collar has a maximum diameter of greater than 0.022m.

- 7In one embodiment of the invention there is provided a method of retrofitting a pumped shower unit to a household vented hot water supply of the type comprising a hot water cylinder, a cold water supply tank located above the hot water cylinder and feeding cold water through a supply pipe to the bottom of the hot water cylinder, a vent pipe extending upwardly from the top of the hot water cylinder towards the cold water supply tank, a first T-joint connected in-line in the vent pipe and a hot water take-off pipe connected to the lateral port of the first T-joint and in fluid communication with the vent pipe for supply of hot water to one or more taps in the household, the method comprising the steps of:

disconnecting the vent pipe from the hot water cylinder;

connecting a first longitudinal port of a second T-joint to the hot water cylinder;

connecting the vent pipe to a lateral port of the second T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 downwardly into the second longitudinal port of the second T-joint until the collar of the injector insert is located on the internal annular seat of the second T-joint and the other end of the injector insert pipe has passed through the second Tjoint and is located internal the hot water cylinder spaced apart from the top of the hot water cylinder; and connecting a pumped shower unit supply pipe to the second longitudinal port of the second T-joint.

This is seen as a particularly effective way of retrofitting a pumped shower unit to a household vented hot water supply. By implementing such a method, it will be possible to avoid having to purchase, stock and use any of a Warix, Techflow, Surrey, Salamander or York flange and instead a simple standard T-joint and injector insert can be used to perform the same function. In addition to this, it is possible to install the pumped shower without having to remove any components that are already connected to the hot water cylinder and that may be effectively welded to the hot water cylinder.

- 8This will be significantly less expensive than the existing solutions and will enable the job to be completed faster than was heretofore the case.

In one embodiment of the invention there is provided a method of retrofitting a pumped shower unit to a household vented hot water supply in which the step of disconnecting the vent pipe from the hot water cylinder further comprises cutting the vent pipe intermediate its ends; and the step of connecting a first longitudinal port of the second Tjoint to the hot water cylinder further comprises connecting the first longitudinal port of the second T-joint to the part of the vent pipe still connected to the hot water cylinder. Again, this will obviate the need to remove any equipment that may be connected to the cylinder and that may have become bonded to the cylinder over time.

In one embodiment of the invention there is provided a method of retrofitting a pumped shower unit to a household vented hot water supply comprising the additional step of setting the distance by which the end of the injector insert internal the hot water cylinder is to be spaced apart from the top of the hot water cylinder by selecting the appropriate length of vent pipe still to be connected to the hot water cylinder prior to cutting the vent pipe. In this way, the depth to which the end of the injector insert is inserted into the tank may be chosen with care to allow for layers of insulation surrounding the hot water cylinder and to ensure that the end of the injector insert is in water, and more specifically, is in the hottest water that is adjacent the top of the hot water cylinder but below the air bubbles that form in the hot water cylinder.

In one embodiment of the invention there is provided a method of retrofitting a pumped shower unit to a household vented hot water supply in which the step of connecting a first longitudinal port of a second T-joint to the hot water cylinder further comprises the steps of: connecting one end of a spacer pipe directly to the hot water cylinder; connecting the other end of the spacer pipe directly to the first longitudinal port of the second T-joint, the spacer pipe thereby being located intermediate the hot water cylinder and the second T-joint. This is seen as a useful alternative way of determining the depth of the bottom of the injector insert pipe in the hot water cylinder.

In one embodiment of the invention there is provided a method of retrofitting a pumped shower unit to a household vented hot water supply comprising the additional

- 9preliminary step of setting the distance by which the end of the injector insert internal the hot water cylinder is to be spaced apart from the top of the hot water cylinder by selecting an appropriate length of a spacer pipe.

In one embodiment of the invention there is provided a household hot water installation comprising:

a vented hot water supply of the type comprising a hot water cylinder, a cold water supply tank located above the hot water cylinder and feeding cold water through a supply pipe to the bottom of the hot water cylinder, a vent pipe extending upwardly from the top of the hot water cylinder towards the cold water supply tank, a first T-joint connected in-line in the vent pipe and a hot water takeoff pipe connected to the lateral port of the first T-joint and in fluid communication with the vent pipe for supply of hot water to one or more taps in the household; and a pumped shower unit including a pumped shower unit supply pipe;

a second T-joint comprising a first longitudinal port, a second longitudinal port and a lateral port; the first longitudinal port being connected to the hot water cylinder, the lateral port being connected to the vent pipe so that the second Tjoint is intermediate the vent pipe and the hot water cylinder, and the second longitudinal port being connected to the pumped shower unit supply pipe; and in which there is provided:

an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the second T-joint, extending downwardly through second T-joint with the collar of the injector insert located on the internal annular seat of the second T-joint and the other end of the injector insert pipe having passed through the second T-joint and located internal the hot water cylinder spaced apart from the top of the hot water cylinder.

By having such an installation, the installation will be less expensive, faster and easier to install than existing installations. The installation does not require any of a Warix,

- 10Techflow, Surrey, Salamander or York flange and instead a simple standard T-joint and injector insert is used to perform the same function in the installation.

In one embodiment of the invention there is provided a household hot water installation in which there is further provided a spacer pipe connected at one end to the first longitudinal port of the second T-joint and connected at its other end to the hot water cylinder, the spacer pipe thereby being located intermediate the hot water cylinder and the second T-joint.

In one embodiment of the invention there is provided a method of connecting a secondary return pipe to a hot water cylinder comprising the steps of:

connecting a first longitudinal port of a T-joint to the top of the hot water cylinder;

connecting a hot water supply pipe to a lateral port of the T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 downwardly into a second longitudinal port of the T-joint until the collar of the injector insert is located on the internal annular seat of the T-joint and the other end of the injector insert pipe has passed through the T-joint and is located internal the hot water cylinder spaced apart from the top of the hot water cylinder; and connecting the secondary return pipe to the second longitudinal port of the Tjoint.

This is seen as a particularly efficient way of connecting a secondary return up to a hot water cylinder that is less expensive and time consuming than the known methods. It will be noticed that it is not necessary to use an Essex flange in order to connect the secondary return up to the hot water cylinder and perhaps even more importantly, it is not necessary to purchase a new hot water cylinder or to drill holes into the hot water cylinder. This is achieved using a simple injector insert according to the invention and a standard T-joint.

- 11 In one embodiment of the invention there is provided a method of connecting a secondary return pipe in which the method comprises the step of connecting a spacer pipe intermediate the first longitudinal port of the T-joint and the hot water cylinder.

In one embodiment of the invention there is provided a method in which the method comprises selecting the length of spacer to determine the distance by which the end of the other end of the injector insert is spaced apart from the top of the hot water cylinder.

In one embodiment of the invention there is provided a household hot water installation of the type comprising:

a hot water cylinder;

a secondary return assembly including a flow pipe for delivering hot water from the hot water cylinder to at least one hot water outlet, a pump, and a secondary return pipe for circulating hot water between the hot water cylinder and the outlet;

the household hot water installation further comprising a T-joint for connecting the flow pipe and the secondary return pipe to the hot water cylinder, the T-joint having a first longitudinal port connected to the hot water cylinder, a lateral port connected to the flow pipe and a second longitudinal port connected to the secondary return pipe;

and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the T-joint, extending downwardly through the T-joint with the collar of the injector insert located on the internal annular seat of the T-joint and the other end of the injector insert pipe having passed through the T-joint and located internal the hot water cylinder spaced apart from the top of the hot water cylinder.

In one embodiment of the invention there is provided a household hot water installation in which there is provided a spacer pipe intermediate the first longitudinal port of the Tjoint and the hot water cylinder.

- 12In one embodiment of the invention there is provided a household hot water installation in which the injector insert is of the type in which the other end of the pipe is closed and in which there is provided an exhaust aperture in a side wall of the pipe adjacent to the closed end.

In one embodiment of the invention there is provided a method of connecting a secondary heat source supply pipe to a hot water cylinder configured to deliver hot water out through a hot water supply pipe at the top of the hot water cylinder, the method comprising the steps of:

connecting the hot water supply pipe to a lateral port of the T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 downwardly into a second longitudinal port of the T-joint until the collar of the injector insert is located on the internal annular seat of the T-joint and the other end of the injector insert pipe has passed through the T-joint and is located internal the hot water cylinder spaced apart from the top of the hot water cylinder; and connecting the secondary heat source supply pipe to the second longitudinal port of the T-joint.

By having such a method, it is possible to connect up a secondary heat source supply to the hot water cylinder without the need for mixing valves and without the need for complex arrangements to ensure the correct flow of hot water from the secondary heat supply into the hot water cylinder. This will provide a hot water installation that is safe in operation as well as being inexpensive and simple to install.

In one embodiment of the invention there is provided a method of connecting a secondary heat source supply pipe to a hot water cylinder in which the method comprises the step of connecting a spacer pipe intermediate the first longitudinal port of the T-joint and the hot water cylinder.

- 13In one embodiment of the invention there is provided a method of connecting a secondary heat source supply pipe to a hot water cylinder in which the method comprises selecting the length of spacer to determine the distance by which the end of the other end of the injector insert is spaced apart from the top of the hot water cylinder.

a hot water cylinder;

a hot water supply pipe at the top of the hot water cylinder for delivering hot water from the hot water cylinder to at least one hot water outlet in the household;

a secondary heat source having a secondary heat source supply pipe to deliver water heated by the secondary heat source to the hot water cylinder;

the household hot water installation further comprising a T-joint for connecting the hot water supply pipe and the secondary heat source supply pipe to the hot water cylinder, the T-joint having a first longitudinal port connected to the hot water cylinder, a lateral port connected to the hot water supply pipe and a second longitudinal port connected to the secondary heat source supply pipe;

This is seen as a particularly advantageous hot water installation that will be less expensive, faster and easier to install than existing offerings. It is possible to provide a secondary heat source supply connected to the hot water cylinder without the need for mixing valves and without the need for complex arrangements to ensure the correct flow

- 14of hot water from the secondary heat supply into the hot water cylinder. This will provide a hot water installation that is safe in operation as well as being inexpensive and simple to install.

In one embodiment of the invention there is provided a household hot water installation in which the injector insert is of the type in which the other end of the pipe is closed and in which there is provided an exhaust aperture in a side wall of the pipe adjacent to the closed end.

In one embodiment of the invention there is provided a household hot water installation in which the hot water cylinder has a cold water feed inlet adjacent the base of the hot water cylinder; and there is provided:

a cold water supply pipe for delivering cold water from a cold water source to the hot water cylinder through the cold water feed inlet;

a secondary heat source return pipe to deliver water from the hot water cylinder to the secondary heat source;

the household hot water installation further comprising a second T-joint for connecting the cold water supply pipe and the secondary heat source return pipe to the hot water cylinder;

the second T-joint having a first longitudinal port connected to the cold water feed inlet of the hot water cylinder, a lateral port connected to one of the cold water supply pipe and the secondary heat source return pipe, and a second longitudinal port connected to the other of the cold water supply pipe and the secondary heat source return pipe;

- 15and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the second T-joint, extending inwardly through the second T-joint with the collar of the injector insert located on the internal annular seat of the second T-joint and the other end of the injector insert pipe having passed through the second T-joint and located internal the hot water cylinder.

In one embodiment of the invention there is provided a household hot water installation in which the lateral port of the second T-joint is connected to the cold water supply pipe and the second longitudinal port of the second T-joint is connected to the secondary heat source return pipe.

In one embodiment of the invention there is provided a method of creating a bias in a piping network having a pair of fluid flow streams joining together into a single combined fluid flow stream using a T-joint, the method comprising the steps of:

connecting a first longitudinal port of the T-joint to an outlet pipe for the combined fluid flow stream;

connecting a lateral port of the T-joint to a first inlet pipe for one of the pair of fluid flow streams to be joined together;

inserting an injector insert into a second longitudinal port of the T-joint, the injector insert comprising an elongate length of pipe having an external diameter less than the internal diameter of the T-joint, the pipe having a collar at one end thereof dimensioned to engage and rest on an internal annular seat of the T-joint, and the pipe having a length so that the other open end of the pipe protrudes inwardly through the T-joint to a point beyond the central axis of the lateral port; and connecting the second longitudinal port of the T-joint to a second inlet pipe for the other of the pair of fluid flow streams to be joined together.

- 16By having such a method, it is possible to create an injector Tee using a simple T-joint and the injector insert according to the invention. Again, this will lower the amount of components that must be carried/kept in stock and will also provide a cost-effective solution when it is necessary to provide a bias in a piping network.

In one embodiment of the invention there is provided an injector Tee comprising:

a standard T-joint having a first longitudinal port, a second longitudinal port and a lateral port; and an injector insert comprising an elongate length of pipe having an external diameter less than the internal diameter of the T-joint, the pipe having a collar at one end thereof dimensioned to engage and rest on an internal annular seat of the first longitudinal port of the T-joint, and the pipe having a length so that the other open end of the pipe protrudes inwardly through the T-joint to a point beyond the central axis of the lateral port.

This is seen as a simple and inexpensive injector Tee to provide and can be created with a standard T-joint and the injector insert. This will further minimize the number of components that need to be carried/kept in stock and will reduce the cost of providing the injector Tee.

In one embodiment of the invention there is provided an injector Tee in which the pipe has a length so that the other open end of the pipe protrudes inwardly through the T-joint to a point beyond the lateral port.

In one embodiment of the invention there is provided an injector Tee in which the pipe has a length so that the other open end of the pipe protrudes inwardly through the T-joint and out through the second longitudinal port.

In one embodiment of the invention there is provided an injector Tee in which the external diameter of the injector insert is less than or equal to 0.8 times the internal diameter of the T-joint.

- 17In one embodiment of the invention there is provided an injector Tee in which the external diameter of the injector insert is less than or equal to 0.75 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector Tee in which the external diameter of the injector insert is less than or equal to 0.70 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector Tee in which the external diameter of the injector insert is greater than 0.3 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector Tee in which in which the external diameter of the injector insert is greater than 0.5 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector Tee in which the external diameter of the injector insert is greater than 0.6 times the internal diameter of the T-joint.

In one embodiment of the invention there is provided an injector Tee in which the collar is frusto-conically shaped, splaying outwardly towards the open end.

In one embodiment of the invention there is provided an injector Tee in which the collar is provided with an annular flange extending outwardly therefrom at its outermost end.

In one embodiment of the invention there is provided an injector Tee in which the pipe has a circumferential weakened section intermediate its ends.

In one embodiment of the invention there is provided an injector Tee in which the pipe has an external diameter of the order of between 0.0127m (½ inch) and 0.0203m (0.8 inch) and the collar has a maximum diameter of greater than 0.0254m (1 inch).

- 18In one embodiment of the invention there is provided an injector Tee in which the pipe has an external diameter of the order of between 0.009m (¾ inch) and 0.015m (³/₅ inch) and the collar has a maximum diameter of greater than 0.01905m (¾ inch).

In one embodiment of the invention there is provided an injector Tee in which the pipe has an external diameter of the order of between 0.014m and 0.022m and the collar has a maximum diameter of greater than 0.028m.

In one embodiment of the invention there is provided an injector Tee in which the pipe has an external diameter of the order of between 0.011m and 0.018m and the collar has a maximum diameter of greater than 0.022m.

In one embodiment of the invention there is provided a method of connecting both of a cold water supply pipe and a secondary heat source return pipe to the cold water feed inlet of a hot water cylinder adjacent the base of the hot water cylinder, the method comprising the steps of:

connecting a first longitudinal port of a T-joint to the cold feed inlet of the hot water cylinder;

connecting one of the cold water supply pipe and the secondary heat source return pipe to a lateral port of the T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 into a second longitudinal port of the T-joint until the collar of the injector insert is located on the internal annular seat of the T-joint and the other end of the injector insert pipe has passed through the T-joint and is located internal the hot water cylinder; and connecting the other of the cold water supply pipe and the secondary heat source return pipe to the second longitudinal port of the T-joint.

This is seen as a particularly effective way of connecting both of a mains or tank fed supply pipe and a secondary heat source return pipe to the bottom of a hot water tank

- 19and ensuring that the cylinder water is not bypassed. This will obviate the need for a mixing valve downstream of the secondary heat source and will reduce the cost of installing the system. This is due to the fact that the configuration neutralizes the pressure as it becomes a neutral pressure point rather than a biased connection.

a hot water cylinder having a cold water feed inlet adjacent the base of the hot water cylinder;

a secondary heat source having a secondary heat source return pipe to deliver water from the hot water cylinder to the secondary heat source;

the household hot water installation further comprising a T-joint for connecting the cold water supply pipe and the secondary heat source return pipe to the hot water cylinder;

the T-joint having a first longitudinal port connected to the cold water feed inlet of the hot water cylinder, a lateral port connected to one of the cold water supply pipe and the secondary heat source return pipe, and a second longitudinal port connected to the other of the cold water supply pipe and the secondary heat source return pipe;

and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the T-joint, extending inwardly through the T-joint with the collar of the injector insert located on the internal annular seat of the T-joint and the other end of the injector insert pipe having passed through the T-joint and located internal the hot water cylinder.

-20This is seen as a particularly useful system/installation to provide. The installation will be less expensive to install than other installations and will require less time to install as there will be less components required.

In one embodiment of the invention there is provided a household hot water installation in which the lateral port is connected to the cold water supply pipe and the second longitudinal port is connected to the secondary heat source return pipe. This is seen as a preferred configuration to ensure that the water for the secondary heat source return pipe is taken from inside the hot water cylinder.

Detailed Description of the Invention

The invention will now be more clearly understood from the following description of some embodiments thereof given by way of example only with reference to the accompanying drawings, in which:Figure 1 is a front view of an injector insert according to the invention;

Figure 2 is a front view of the injector insert of Figure 1 mounted in a standard Tjoint, spacer pipe and “311” fitting;

Figure 3 is a view similar to Figure 2 with the T-Joint, spacer pipe and “311” fitting shown in ghost outline;

Figure 4 is an exploded view of Figure 2 also showing a “312” fitting;

Figure 5 is a diagrammatic representation of the assembly shown in Figure 2 mounted on a hot water cylinder;

Figure 6 is a diagrammatic view of the operation of a York flange;

Figure 7 is a more detailed diagrammatic view of the operation of a York flange;

-21 Figure 8 is a diagrammatic representation of a retrofitted pumped shower installation known in the art;

Figure 9(a) is a diagrammatic representation of a retrofitted pumped shower installation according to the invention incorporating the injector insert and a standard T-joint;

Figure 9(b) is an enlarged view of the encircled portion of Figure 9(a);

Figure 10 is a diagrammatic representation of a secondary return installation known in the art;

Figure 11(a) is a diagrammatic representation of a secondary return installation according to the invention incorporating the injector insert and a standard T-joint;

Figure 11(b) is an enlarged view of the encircled portion of Figure 11(a);

Figure 12 is a diagrammatic representation of a secondary heat source installation known in the art;

Figure 13(a) is a diagrammatic representation of a secondary heat source installation according to the invention incorporating the injector insert and a standard T-joint;

Figure 13(b) is an enlarged view of the encircled portion of Figure 13(a);

Figure 14(a) is a diagrammatic representation of an alternative embodiment of a secondary heat source installation according to the invention incorporating the injector insert and a standard T-joint;

Figure 14(b) is an enlarged view of the encircled portion of Figure 14(a);

-22Figure 15 is a front view of an alternative embodiment of an injector insert according to the invention;

Figure 16 is a diagrammatic view of an injector Tee known in the art;

Figure 17 is a side view of an injector Tee according to the invention with the Tjoint shown in ghost outline;

Figure 18 is a perspective view of an alternative embodiment of the injector Tee according to the invention; and

Figure 19 is view similar to Figure 18 with the T-joint shown in ghost outline.

Referring to Figures 1 to 4 inclusive, there is shown an injector insert, indicated generally by the reference numeral 1, comprising an elongate length of pipe 3 having a collar 5 at one end thereof.

The pipe 3 has an external diameter, D_E, less than the internal diameter, D_b of a standard T-joint 7. The collar 5 is dimensioned to engage and rest on an internal annular seat 9 of the T-joint. More specifically, the diameter of the collar, D_c, is greater than the internal diameter, D_b of the standard T-joint.

The pipe 3 has an external diameter D_E of the order of less than or equal to 0.8 times the internal diameter D| of the T-joint, preferably less than or equal to 0.75 times the internal diameter D| of the T-joint and potentially less than or equal to 0.7 times the internal diameter D| of the T-joint. The external diameter D_E of the pipe is however greater than or equal to 0.3 times the internal diameter D| of the T-joint, preferably greater than or equal to 0.5 times the internal diameter D| of the T-joint and ideally greater than or equal to 0.6 times the internal diameter D| of the T-joint. In the embodiment, shown, the T-joint is a standard T-joint having a 1 inch (0.0254m) internal diameter. The pipe 3 has an external diameter of 0.0191m (0.75 inch) and the collar has a maximum diameter of greater than 0.0254m (1 inch).

-23In the embodiment shown in Figures 1 to 4 inclusive, there are provided a plurality of exhaust apertures 11 adjacent the other end 13 of the pipe. At least some of the exhaust apertures are arranged longitudinally along the length of the pipe and at least some of the exhaust apertures 11 are arranged circumferentially around the pipe, evenly spaced about the circumference of the pipe.

The end 13 of the pipe may be either open or closed depending on the intended function of the injector insert and the exhaust apertures may or may not be provided, again depending on the intended function of the injector insert as will be elaborated upon in greater detail below.

The collar 5 is frusto-conical in shape, splaying outwardly towards its open free end. In this way, as the injector insert is inserted into the T-joint, the frusto-conically shaped collar will have a self-centring effect on the injector insert, obviating the possibility of the injector insert blocking the lateral port of the T-joint.

Referring specifically to Figure 4, the T-joint 7 comprises a first longitudinal port 15, a lateral port 17 and a second longitudinal port 19, as is known in the art. There is further shown a “311” fitting 21 having a male threaded connector for engagement of a tank and a “312” fitting 23 having a threaded female connector which may be used instead of the “311” fitting depending on the corresponding connection on the tank. A spacer pipe 25 is placed intermediate the “311” fitting 21 and the T-joint 7.

In use, in order to install the assembly on a hot water cylinder (not shown), the “311” fitting 21 (or “312” fitting if appropriate) is connected to the corresponding fitting on the hot water cylinder. Once in place, one end 27 of the spacer pipe 25 is inserted into the free end 29 of the “311” fitting and the compression fitting on the end 27 of the “311” fitting is tightened thereby sealing the connection between the spacer pipe 25 and the “311” fitting 21. Thereafter, the first longitudinal port 15 of the T-joint 7 is connected to the other free end 31 of the spacer pipe and the compression fitting on the first longitudinal port 15 of the T-joint is tightened thereby sealing the connection between the spacer pipe 25 and the T-joint. Once the T-joint is in position, the end 13 of the injector insert is lowered into the T-joint until the end 13 passes through the T-joint 7, the spacer pipe 25 and the “311” fitting 21 and is positioned inside the hot water cylinder. Further

-24movement of the injector insert into the hot water cylinder is prevented by the collar 5 resting on the annular seat 9 internal the T-joint 7. The length of the spacer pipe 25 determines the depth to which the end 13 of the injector insert protrudes downwardly into the hot water cylinder and an appropriately sized spacer pipe may be chosen to ensure that the end 13 of the injector insert is at the correct depth in the hot water cylinder.

It will be appreciated that in other configurations the spacer pipe 25, the “311” fitting 21 and the “312” fitting may be omitted. For example, if there is a vent pipe (not shown) or other pipe (not shown) already connected to the hot water cylinder, instead of providing a spacer pipe 25 and “311” or “312” fitting, the pipe that is already connected to the hot water cylinder may be cut and the T-joint may be connected to the stub of the cut pipe. The pipe that is already connected to the hot water cylinder would be cut at the appropriate height to ensure that the end 13 of the injector insert was at the desired height in the hot water cylinder. Furthermore, in the embodiment shown, the T-joint has a compression fitting on the first longitudinal port 15 however instead of a compression fitting, the first longitudinal port could be provided with a male threaded coupling or a female threaded coupling and this male or female threaded coupling could be connected directly to a complementary coupling on the hot water cylinder. In this way, there is no need to provide a spacer pipe or to cut an existing pipe connected to the hot water cylinder.

In such a case, the injector insert could be cut to the desired length to ensure that the end 13 of the injector insert is at the correct height inside the hot water cylinder. Alternatively, several injector inserts of different lengths could be provided and the appropriate length injector insert could be chosen to ensure that the end 13 of the injector insert is at the correct height in the hot water cylinder.

Referring now to Figure 5, there is shown a diagrammatic representation of the assembly shown in Figure 2 mounted on a hot water cylinder 31, only part of which is shown. The end 13 of the injector insert 1 protrudes downwardly into the hot water cylinder 31 and is spaced apart from the top 33 of the hot water cylinder to a position, W, where there is water in the cylinder and a position that is substantially free of air bubbles. The air bubbles (not shown) will travel upwards in the tank and gather at the top of the

-25tank before passing up through the spacer pipe 25 and out the lateral port 17 of the Tjoint. A vent pipe (not shown) will typically be connected to the lateral port 17. The air bubbles are prevented from passing upwardly and out through the second longitudinal port 19 of the T-joint by the seal formed between the collar 5 and the internal annular flange and/or the seal formed between a pipe (not shown) inserted into the second longitudinal port and the second longitudinal port ofthe T-joint.

The operation and benefits of the injector insert will be more thoroughly understood from a brief description of Figures 6 and 7, which demonstrate the operation of a York flange. A York flange is one type of flange that is commonly used when a pumped shower is retrofitted into a vented hot water cylinder. In many systems, air bubbles 33 are entrapped in the incoming water entering the hot water cylinder and the air bubbles gather at the top of the hot water cylinder. It is necessary to vent these air bubbles from the hot water cylinder in order to ensure continued operation of the system. It is highly undesirable to allow air bubbles into a pump as over time this will damage the pump and leads to a reduction in pump efficiency. A York flange, indicated generally by the reference numeral 41, may be mounted at the top of a hot water cylinder. The York flange 41 has a downwardly depending inlet pipe 43 that protrudes downwardly into the tank to a level substantially below the air bubbles in the tank. Water is drawn up through the inlet pipe and discharged through the lateral port 44 of the York flange 41 from where it is delivered to a pump, substantially air free. At the same time, the York flange 41 provides a fluid passageway up through the York flange 41 to a longitudinal port 45 of the York flange. Water for other outlets in the household such as taps (not shown) and the air bubbles 33 travel up through this longitudinal port to a vent pipe 47 to be delivered to the other outlets and to allow the air bubbles to be vented to the atmosphere. Depending on the connection provided on the cylinder and the outlet piping configuration required, any one of a Warix flange, a Surrey flange, a Techflow flange and a Salamander flange could be used instead of the York flange to equal effect.

Referring once more to Figure 5, it can be seen that the injector insert, in conjunction with a standard T-joint, effectively carries out the same function as the York flange 41 (or indeed any one of the Warix flange, a Surrey flange, a Techflow flange and a Salamander flange). Air bubbles congregate at the top of the tank 33 and travel upwards through the T-joint and out of the lateral port 17 of the T-joint 7. At the same time, water

-26that is substantially free of air bubbles is drawn through the bottom 13 of the pipe 3 and passed upwards through the injector insert and out of the second longitudinal port 19 of the T-joint. The second longitudinal port 19 of the T-joint will be connected to the pump in this instance and the lateral port 17 will be connected to a vent pipe for supply of water to the other outlets in the household and to permit venting of air bubbles from the hot water tank. The injector insert and the standard T-joint are significantly less expensive than the other flanges available on the market and do not require removal of the existing connections to the hot water cylinder, thereby simplifying installation significantly.

Referring now to Figure 8, there is shown a diagrammatic representation of a hot water installation 81 having a retrofit pumped shower unit that is known in the art. The hot water installation 81 comprises a hot water cylinder 31, a supply tank 83 for supplying cold water to the hot water cylinder 31, and a vent pipe 85 extending upwardly from the top 33 of the hot water cylinder 31 for conveying hot water from the tank and for venting air out of the system. A hot water supply pipe 86 branches off the vent pipe at T-joint 87 to supply taps and other hot water outlets (not shown) in the installation. The retrofit pumped shower unit comprises a pump 88 and is also connected to the vent pipe 85 by a T-joint. Although the configuration shown appears simple and straightforward, there are significant shortcomings with this configuration. It will be understood that there will be a static head of water in the vent pipe 85 in line with the level of water in the supply tank 83. Importantly, when the pump 88, typically a single or twin impeller pump starts up, water will be rapidly sucked into the pump 88 and this water may be routed from the vent pipe above the T-joint 89 instead of from the hot water cylinder 31 and the vent pipe 85 below the T-joint 89. If this happens, as all the water is drawn into the pump, air will then be drawn into the pump 88 through the upper part of the vent pipe. This can cause substantial damage to the pump and can impede operation of the pumped shower unit.

Referring to Figures 9(a) and 9(b), there is shown a hot water installation, indicated generally by the reference numeral 91, that overcomes the problems of the installation shown in Figure 8 using the injector insert according to the present invention, and where like parts have been given the same reference numeral as before. The first longitudinal port 15 of a T-joint 7 is connected to the top of the hot water cylinder 31 and the injector insert 1 is inserted through the second longitudinal port 19 of the T-joint and into the

-27tank. The vent pipe 85 is connected to the lateral port 17 of the T-joint and a conduit 93 feeding water from the hot water cylinder to the pump 88 is connected to the second longitudinal port 19 of the T-joint. In this way, when the pump is turned on, it will draw water directly from the second longitudinal port 19 which in turn is in communication with the injector insert which has one end 13 in the water in the tank. This will obviate the possibility of large amounts of air being drawn into the pump 88. Air bubbles in the hot water cylinder 31 will travel to the top of the hot water cylinder and can escape through the lateral port 17 of the T-joint 7 to the vent pipe. Furthermore, hot water may be delivered through the vent pipe 85 and the hot water supply pipe 86 to the other outlets in the installation.

In the embodiment shown in Figures 9(a) and 9(b), the pipe 3 of the injector insert has a plurality of exhaust apertures 11 however it will be understood that for this function, drawing water out of the hot water cylinder, the end 13 of the pipe 3 may be open and the exhaust apertures need not be provided.

Referring to Figure 10, there is shown a hot water installation having a secondary return known in the art, indicated generally by the reference numeral 101, where like parts have been given the same reference numeral as before. The hot water installation with a secondary return effectively has a circulating pump 103 that continuously draws hot water from the top of the hot water cylinder 33 and delivers that hot water in a loop through a hot water supply pipe 86 to a plurality of outlets 105(a)-105(c) (in this case a pair of sinks 105(a), 105(b) and a bath105(c)) in the installation and back to the hot water cylinder via a secondary return pipe 107. In this way, hot water is available instantaneously at each of the hot water outlets 105(1 )-105(c). The secondary return pipe 107 is connected to the hot water cylinder 31 by way of a dedicated return port 109 spaced apart from the top 33 of the hot water cylinder but still in close proximity to the upper part of the hot water cylinder 31. If a dedicated port on the existing tank is not provided and it is desired to provide a secondary return in a hot water installation, it is necessary to either purchase a new hot water cylinder with a dedicated port or to drill into the hot water cylinder and use a Essex Flange to connect up the secondary return to the hot water cylinder. Neither of these solutions is particularly appetising as they are, generally speaking, expensive and time consuming.

-28Referring to Figures 11(a) and 11(b), there is shown a hot water installation, indicated generally by the reference numeral 111, that overcomes the problems of the installation shown in Figure 10 using the injector insert according to the present invention, and where like parts have been given the same reference numeral as before. The hot water installation comprises a T-joint 7 connected to the top of the hot water cylinder and an injector insert 1 passed through the second longitudinal port 19 of the T-joint and extending downwardly into the tank from where it can dispense water returning from the hot water outlets 105(a)-105(c). A hot water supply pipe 86 is connected to the lateral port 17 of the T-joint 7 and the secondary return pipe 107 is connected to the second longitudinal port 19 of the T-joint. The first longitudinal port 15 of the T-joint is connected to the hot water cylinder 31.

In use, hot water is drawn from the top 33 of the hot water cylinder 31 by the circulating pump 103. The hot water is drawn out through the lateral port 17 of the T-joint 7 and travels to the hot water outlets 105(a)-105(c) along the hot water supply pipe 86. The slightly cooler hot water returns to the hot water cylinder via the secondary return pipe 107 and passes into the cylinder through the second longitudinal port 19 of the T-joint and through the injector insert 1 pipe 3 before being deposited into the hot water cylinder 31 below the top of the hot water cylinder out of the end 13 of the pipe 3. The water is continuously circulated in this fashion in order to ensure that there is hot water available practically instantaneously at the hot water outlets 105(a)-105(c).

It will be appreciated that in this embodiment, as water is being delivered into the hot water cylinder adjacent the top of the hot water cylinder, it is envisaged that it will be advantageous to have a pipe 3 with a closed end 13 and at least one exhaust aperture 11 along the length of the pipe 3 as shown. In this way, the relatively hot water returning from the secondary return pipe will be kept towards the top of the cylinder rather than being directed towards the bottom of the cylinder for mixing with other colder water in the hot water cylinder. Furthermore, although the connections of hot water supply pipe 86 and secondary return pipe 107 shown in Figure 11(a) are deemed preferred, it is envisaged that the hot water supply pipe 86 and the secondary return pipe 107 could be connected to the other of the longitudinal port 19 and the lateral port 17 respectively. Indeed, in such a case, the injector insert 1 may be shortened to the point where it protrudes into the T-joint to a point at or just beyond the central axis of the lateral port

-2917. However, this second, alternative configuration (particularly with shortened injector insert) may be sub-optimal as some mixed temperature water may be delivered if the end of the injector insert is not below the level of the cylinder dome.

In addition to the foregoing, in Figure 11(b), the hot water supply pipe 86 and the secondary return pipe 107 have been omitted for clarity and the direction of the lateral port has been reversed from the orientation shown in Figure 11(a) however this merely demonstrates the flexibility of positioning of the lateral port 17.

Referring now to Figure 12, there is shown a diagrammatic representation of a hot water installation, indicated generally by the reference numeral 121, including a secondary heat source (not shown) and a heat exchanger 122. For reasons of clarity, like parts have been given the same reference numeral as before. The heat exchanger 122 comprises a primary side 123 connected up to a secondary heat source such as, but not limited to, a boiler or a stove, and a secondary side 124 connected up to the hot water cylinder. The hot water installation 121 further comprises a circulation pump 125 and is configured to operate the circulation pump 125 to draw cold water from the base of the hot water cylinder. The cold water is passed through the secondary side 124 of the heat exchanger 122, heating the cold water as it passes through the secondary side, and the thus heated water is then delivered back to the hot water cylinder adjacent the top of the hot water cylinder.

The cold water supply tank 83 delivers cold water to the bottom of the hot water cylinder through cold water supply pipe 126. A T-joint 127 is connected in-line in the cold water supply pipe 126 to provide the feed pipe 129 of cold water from the base of the hot water cylinder to the secondary side 124 of the heat exchanger 122. A mixing valve 128 is provided downstream of the secondary side 124 of the heat exchanger 122 to ensure that the water passing back to the vent pipe 85 and in turn to the hot water cylinder 31 is at or near the correct temperature. This is necessary as hot water from the heat exchanger could bypass the cylinder 31 and be delivered directly from the secondary side of the heat exchanger to a water outlet if a tap is turned on along the hot water supply line 86. Without a mixing valve 128, the water from the secondary side could be at scalding temperature and this could injure an unsuspecting individual or indeed the water from the secondary side could be lukewarm leading to user dissatisfaction.

-30There are a number of problems with the hot water installation 121 shown in Figure 12. First of all, the installation is relatively expensive to install as it requires a mixing valve which is expensive. Without the mixing valve, the installation can pose a significant health hazard to users as scalding hot water may bypass the hot water cylinder and be delivered directly to a water outlet from the secondary side of the heat exchanger. Another problem with this configuration is that the temperature of the incoming water is also not always consistent. By having a T-joint in the cold water supply pipe, when the circulation pump 125 is operated, there is a possibility that the water will not be drawn from the cylinder but instead will be drawn from the cold water supply tank. This is disadvantageous as it will increase the length of time required to heat the water in the hot water cylinder, thereby detracting from one of the main benefits of the secondary heat supply.

Referring to Figures 13(a) and 13(b) and to Figures 14(a) and 14(b), there are shown alternative configurations of hot water installations, indicated generally by the reference numerals 131 and 141 respectively, that address one or more of the problems associated with the hot water installation described with reference to Figure 12. Referring first of all to Figures 13(a) and 13(b), where like parts have been given the same reference numeral as before, there is shown a hot water installation 131 having a secondary heat supply (not shown) and a heat exchanger 122 having a primary side 123 connected to the secondary heat supply and a secondary side 124 connected to the hot water cylinder 31. The hot water installation 131 comprises a T-joint 7 and an injector insert 1 for connecting the cold water supply pipe 126 to the hot water cylinder 31 and the secondary side 124 inlet of the heat exchanger 122 to the hot water cylinder 31.

It can be seen from Figure 13(a) that the T-joint 7 is mounted in close proximity, preferably directly to, the hot water cylinder 31 adjacent but spaced apart from the base of the hot water cylinder 31. Referring specifically to Figure 13(b), the first longitudinal port 15 is connected up to the hot water cylinder at the cold feed inlet to the hot water cylinder. An injector insert 1 is inserted through the second longitudinal port 19 of the injector insert 1 until the collar 5 of the injector insert abuts against the internal annular seat 9 and the open end 13 of the pipe 3 of the injector insert 1 is positioned inside the hot water cylinder. The cold water supply pipe 126 is then connected up to the second

-31 longitudinal port 19 of the T-joint 7 behind the collar 5 of the injector insert. Finally, the feed pipe 129 for cold water from the hot water cylinder 31 to the inlet of the secondary side of the heat exchanger is connected to the lateral port 17 of the T-joint 7.

By having such a configuration, cold water from the cold water supply tank 83 that travels down along the cold water supply pipe is delivered directly into the hot water cylinder. In addition to this, cold water from the hot water cylinder for feeding to the secondary side 124 of the heat exchanger 122 is taken from the hot water cylinder. In other words, the cold water directed to the secondary side of the heat exchanger is taken directly from the hot water cylinder and is not bypassed by cold water coming directly from the cold water supply tank 83. This ensures that the hot water cylinder can be brought up to temperature as quickly as possible.

It will be understood that the connection of the cold water supply pipe 126 and the feed pipe 129 could be reversed without negatively impacting upon the operation of the hot water installation. For example, the cold water supply pipe 126 from the cold water supply tank 83 could be connected to the lateral port 17 of the T-joint and the feed pipe 129 could be connected to the second longitudinal port 19 of the T-joint. In this configuration, the water from the cold water supply pipe will still be delivered directly into the hot water cylinder and the water for the feed pipe 129 will still be drawn directly from the hot water cylinder and the water to the secondary side of the heat exchanger will not be able to be taken directly from the cold water supply pipe and the cold water supply tank 83.

In the embodiment shown in Figure 13(a) and 13(b), the end of the pipe is open and there are no exhaust apertures. This is possible as the pipe is either being used to drain water (if the second longitudinal port is connected to the feed pipe 129) from the hot water cylinder or is being used to deliver water laterally (if the second longitudinal port is connected to the cold water supply pipe 126) into the hot water cylinder. The lateral introduction of water into the tank will not disrupt the stratification of water in the hot water tank and therefore flow calming may not be required. Of course, it will be important when delivering cold water into the hot water cylinder, not to disturb the silt and detritus at the bottom of the tank and the open end may help to provide a calmer more uniform flow into the hot water cylinder.

-32Referring now to Figures 14(a) and 14(b), there is shown an alternative configuration of hot water installation, indicated generally by the reference numeral 141, where like parts have been given the same reference numeral as before. The hot water installation 141 differs from the hot water installation shown in Figures 12, 13(a) and 13(b) in that there is an alternative arrangement for the hot water being delivered from the secondary side 124 of the heat exchanger 122 to the hot water cylinder. In this embodiment, the first longitudinal port 15 of a T-joint 7 is connected to the top 33 of the hot water cylinder 31. The vent pipe 85 I hot water supply pipe 86 is connected up to the lateral port 17 of the T-joint 7. An injector insert is inserted into the second longitudinal port 19 of the T-joint 7 until the collar 5 at one end of the injector insert 1 sits on the internal annular seat 9 of the T-joint 7 and the other end 13 of the injector insert is located internal the hot water tank a distance (referred to as the plunge depth) below the top 33 of the tank. The supply pipe 143 from the secondary side 124 of the heat exchanger is connected up to the secondary longitudinal port 19 of the T-joint 7 connected to the top of the hot water cylinder. By having such an arrangement, hot water being drawn from the hot water cylinder will be drawn from the top of the hot water cylinder and hot water coming from the secondary side 124 of the heat exchanger is delivered directly into the hot water cylinder below the top of the hot water cylinder. In this way, the water coming from the heat exchanger cannot be fed directly to the hot water supply pipe 86 and instead it must first be delivered into the hot water cylinder. This will obviate the likelihood of users of the installation being scalded by hot water being delivered directly from the heat exchanger and also avoids the need for a mixing valve. This provides an installation that is safer and more cost effective to install.

Referring specifically to Figure 14(b), it will be noted that the pipe 3 of the injector insert is provided with a plurality of exhaust apertures. Furthermore, the pipe 3 has a closed end 13. In this way, hot water coming from the secondary side of the heat exchanger 122 will pass down through the pipe 3 and will travel from the pipe laterally out of the exhaust apertures 11. This will obviate disruption of the stratification layers in the hot water cylinder and will ensure that the heating of the hot water in the tank is very uniform from top to bottom as the water is heated. This will also ensure that the hottest water is available for delivery at the top of the hot water cylinder 31.

-33In the embodiment shown in Figure 14(a), the same arrangement for the cold water feed to the tank and the heat exchanger as illustrated in Figure 13(a) was used. This is not essential although it is envisaged that it will provide the most effective hot water installation with a secondary heat supply according to the present invention. However, a hot water installation with the arrangement for the delivery of hot water from the secondary side of a heat exchanger as illustrated in Figure 14(a) and the cold water feed to the hot water cylinder and the secondary side of the heat exchanger known in the art and as shown in Figure 12 is still deemed as an advantageous embodiment of the present invention.

In the embodiments shown in Figures 11(a), 11(b), 13(a), 13(b), 14(a) and 14(b), the hot water installations are vented hot water installations fed by a cold water supply tank in an attic or other location above the hot water cylinder. This configuration is not essential and the cold water supply could be mains fed if desired.

Referring now to Figure 15, there is shown an alternative embodiment of injector insert according to the invention, indicated generally by the reference numeral 151, where like parts have been given the same reference numeral as before. The injector insert 151 comprises an elongate length of pipe 3 with a collar 5 at one end thereof. The other end 13 of the pipe is closed and there are provided a plurality of exhaust apertures 11 in the pipe 3. The injector insert 151 differs from the injector insert 1 shown in the previous embodiments in that it is provided with at least one, and in this case two, weakened portions 153,155 along its length. The weakened portions 153, 155 are provided by grooves machined into the side of the pipe 3.

The weakened portions or grooves 153, 155 in the pipe allow the pipe to be shortened to the desired length for use as an injector insert in an injector-Tee (as will be described in greater detail below) by cutting the pipe 3 at the weakened section 153, or for use as an feed inlet for a retrofit pumped shower (as described above with reference to Figures 9(a) and 9(b)) or a lateral feed inlet or outlet for a cold water feed of a hot water cylinder in an installation having a secondary supply (as described above with reference to Figures 13(a), 13(b), 14(a) and 14(b)) by cutting the pipe 3 at the weakened section 155. In the embodiment shown, only two weakened sections 153, 155 are provided however

-34more weakened sections could be provided if desired to allow adjustability of the plunge depth.

In addition to the foregoing, it will be seen that the frusto-conical collar 5 of the injector insert 151 has an annular flange 157 at its widest, outermost end. This annular flange 157 may assist in forming a positive seal with the internal annular seat 9 of a T-joint. Alternatively or in addition to this, the flange 157 may assist in providing a positive seal with the end of the conduit (not shown) that follows the injector insert into the second longitudinal port 19 of the T-joint.

Referring now to Figure 16, there is shown an injector Tee known in the art, indicated generally by the reference numeral 161. The injector Tee comprises a first longitudinal port 163, a lateral port 165 and a second longitudinal port 167. The injector Tee 161 further comprises a venturi nozzle 169 internal the injector Tee.

In use, when it is desired to combine two flows together into a single flow and ensure that the flows will travel in the intended direction (i.e. the direction of the combined single flow), an injector Tee such as the one shown in Figure 16 is used. For example, in a household heating system, hot water fed to the radiators will have to return to a boiler for reheating before being recirculated back out to the radiators once more. Similarly, hot water that is fed to a heating coil internal a cylinder will have to be recirculated back to the boiler for reheating before being delivered back to the heating coil once more. There is a danger that if a simple T-joint is used, if one of the circuits (i.e. the radiators or the heating coil) is not on, cooled water coming back from the other circuit could be redirected to the circuit that is not currently operational, leading to an inefficient system, the injector Tee overcomes this problem by introducing a bias into the T-joint and thereby ensuring that the flows travel in the intended direction.

Referring again to Figure 16, the second longitudinal port 167 may, for example, be connected to a radiator return pipe. The lateral port 165 may, for example, be connected to a cylinder coil return pipe. The flows from the second longitudinal port 167 and the lateral port 165 must be combined and conveyed to the boiler (not shown) out through the first longitudinal port 163. By introducing the venturi nozzle 169 into the body of the injector Tee, a “bias” is created in the injector Tee as the outlet of the venturi nozzle 169

-35and hence the entry point of heating fluid returning from the radiators through the second longitudinal port 167 into the mixed combined flow is beyond the central axis of the lateral port 165. This will obviate the likelihood of heating fluid from the radiator circuit flowing out of the venturi nozzle 169 (i.e. from the second longitudinal port 167) and up through the lateral port 165 into the cylinder coil and similarly will obviate the likelihood of heating fluid flowing out of the lateral port 165 from the cylinder coil and back up through the venturi nozzle and through the second longitudinal port 167 into the radiator circuit.

Referring now to Figure 17, there is shown an injector Tee according to the present invention, indicated generally by the reference numeral 171, where like parts have been given the same reference numeral as before. The injector Tee 171 comprises a standard T-joint 7 having a first longitudinal port 15, a lateral port 17 and a second longitudinal port 19. An injector insert 151, cut down to size so that the pipe of the injector insert passes through the T-joint to a point where the open end 13 of the injector insert is positioned beyond the central longitudinal axis, L, of the lateral port 17 when the collar 5 is engaged on the internal annular seat 9 of the T-joint. The injector insert 151 may of course be provided pre-cut in this or a range of sizes for different applications. It can be seen from the foregoing that an injector Tee may be constructed quickly from a standard T-joint and an injector insert and this will enable fewer components to be held in stock and provides a useful inexpensive alternative to the known offerings.

Referring now to Figures 18 and 19, there is shown an alternative embodiment of injector Tee according to the invention, indicated generally by the reference numeral 181, where like parts have been given the same reference numeral as before. In this embodiment, the injector Tee has an injector insert 151 that passes all the way through the T-joint and this will work effectively as an injector Tee.

Throughout this specification, reference has been made to “cold” water and “hot” water. It will be understood by the skilled addressee what is meant by these in the context of the description and the hot water installations described and that they are often relative terms. For example, the cold water return from a radiator circuit may be at or close to 60°C which is hot by most standards but is relatively cold to the hot feed going out to the radiators which may be at 70°C. Similarly, as the “cold” water from the hot water cylinder is fed to the secondary side of the heat exchanger, if the circuit is left on long enough,

-36the cold water being passed to the secondary side of the heat exchanger will of course be relatively hot as all the water in the hot water cylinder has been heated over time. However, water exiting the heat exchanger will have been heated up even further.

In addition to the foregoing, reference is made to the internal diameter, D_b of the T-joint and the relationship between the external diameter of the injector insert 1, 151 and the internal diameter of the T-joint. It will be appreciated that in the longitudinal direction in a T-joint there are two different internal diameters of the T-joints. The T-joints are typically wider at both ends to allow the insertion of a pipe therein (unless an external or internal thread in the pipe is provided). This wider portion of the pipe is delimited by the internal annular seat, against which the end of the inserted pipe abuts against. From the internal annular seat at either end inwards to the centre of the T-joint, the internal diameter of the pipe is relatively constant but less than it is at the first and second longitudinal ports of the T-joint. Accordingly, there is a narrow internal diameter (i.e. that internal diameter between the internal annular seat of the first longitudinal port and the internal annular seat of the second longitudinal port) and a wide internal diameter (i.e. that internal diameter from the internal annular seat to the adjacent longitudinal port). For the avoidance of doubt, when referring to the internal diameter and specifically when referring to the dimensions of the external diameter of the pipe relative to the internal diameter of the T-joint, reference is being made to the narrow internal diameter of the Tjoint (i.e. that internal diameter between the internal annular seat of the first longitudinal port and the internal annular seat of the second longitudinal port).

In the claims and specification, reference is made to adapting a standard T-joint. It will be understood that a standard T-joint is one which is normally carried in the inventory of a plumber and/or an equipment supplier and not a bespoke, specially moulded piece that is provided and dimensioned specifically to fit the injector insert. In other words, the injector insert will be suitable for use with the T-joints that are commonly available on the market. The injector insert will adapt the standard T-joint into an alternative functional piece of equipment such as an injector Tee or a device that is functionally equivalent to a Warix, Techflow, Surrey, Essex, Salamander or York flange at a fraction of the cost and complexity.

-37In this specification the terms “comprise, comprises, comprised and comprising” and the terms “include, includes, included and including” are all deemed totally interchangeable and should be afforded the widest possible interpretation. The invention is not limited to the embodiments hereinbefore described which are provided for the purposes of example only and may be varied in both construction and detail within the scope of the appended claims.

Claims

Claims:

(1) An injector insert for adapting a standard T-joint, the injector insert comprising an elongate length of pipe having an external diameter less than the internal diameter of the T-joint, the pipe having a collar at one end thereof dimensioned to engage and rest on an internal annular seat of the T-joint.
(2) An injector insert for adapting a standard T-joint as claimed in claim 1 in which the external diameter of the injector insert is less than or equal to 0.8 times the internal diameter of the T-joint.
(3) An injector insert for adapting a standard T-joint as claimed in claim 1 in which the external diameter of the injector insert is less than or equal to 0.75 times the internal diameter of the T-joint.
(4) An injector insert for adapting a standard T-joint as claimed in claim 1 in which the external diameter of the injector insert is less than or equal to 0.70 times the internal diameter of the T-joint.
(5) An injector insert for adapting a standard T-joint as claimed in any preceding claim in which the external diameter of the injector insert is greater than 0.3 times the internal diameter of the T-joint.
(6) An injector insert for adapting a standard T-joint as claimed in any of claims 1 to 4 in which in which the external diameter of the injector insert is greater than 0.5 times the internal diameter of the T-joint.
(7) An injector insert for adapting a standard T-joint as claimed in any of claims 1 to 4 in which in which the external diameter of the injector insert is greater than 0.6 times the internal diameter of the T-joint.
(8) An injector insert for adapting a standard T-joint as claimed in any preceding claim in which the other end of the pipe is open.

-39(
9) An injector insert for adapting a standard T-joint as claimed in any of claims 1 to 7 in which the other end of the pipe is closed and in which there is provided an exhaust aperture in a side wall of the pipe adjacent to the closed end.
(10) An injector insert for adapting a standard T-joint as claimed in claim 9 in which there are provided a plurality of exhaust apertures aligned longitudinally in the side wall of the pipe adjacent to the closed end.
(11) An injector insert for adapting a standard T-joint as claimed in claim 9 or 10 in which there are provided a plurality of exhaust apertures in the side wall of the pipe adjacent to the closed end, circumferentially spaced around the pipe.
(12) An injector insert for adapting a standard T-joint as claimed in claim 11 in which the plurality of apertures circumferentially spaced around the pipe are evenly spaced around the pipe.
(13) An injector insert for adapting a standard T-joint as claimed in any preceding claim in which the collar is frusto-conically shaped, splaying outwardly towards the open end.
(14) An injector insert for adapting a standard T-joint as claimed in claim 13 in which the collar is provided with an annular flange extending outwardly therefrom at its outermost end.
(15) An injector insert for adapting a standard T-joint as claimed in any preceding claim in which the pipe has a circumferential weakened section intermediate its ends.
(16) An injector insert for adapting a standard T-joint as claimed in any preceding claim in which the pipe has an external diameter of the order of between 0.0127m (½ inch) and 0.0203m (0.8 inch) and the collar has a maximum diameter of greater than 0.0254m (1 inch).

(17) An injector insert for adapting a standard T-joint as claimed in claims 1 to 15 in which the pipe has an external diameter of the order of between 0.009m (¾ inch) and 0.015m (³/₅ inch) and the collar has a maximum diameter of greater than η 0.01905m (%inch). (18) An injector insert for adapting a standard T-joint as claimed in claims 1 to 15 in which the pipe has an external diameter of the order of between 0.014m and 0.022m and the collar has a maximum diameter of greater than 0.028m. 10 (19) An injector insert for adapting a standard T-joint as claimed in claims 1 to 15 in which the pipe has an external diameter of the order of between 0.011m and 0.018m and the collar has a maximum diameter of greater than 0.022m.

-41 (20) A method of retrofitting a pumped shower unit to a household vented hot water supply of the type comprising a hot water cylinder, a cold water supply tank located above the hot water cylinder and feeding cold water through a supply pipe to the bottom of the hot water cylinder, a vent pipe extending upwardly from the top of the hot water cylinder towards the cold water supply tank, a first T-joint connected in-line in the vent pipe and a hot water take-off pipe connected to the lateral port of the first T-joint and in fluid communication with the vent pipe for supply of hot water to one or more taps in the household, the method comprising the steps of:

disconnecting the vent pipe from the hot water cylinder;

connecting a first longitudinal port of a second T-joint to the hot water cylinder;

connecting the vent pipe to a lateral port of the second T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 downwardly into the second longitudinal port of the second T-joint until the collar of the injector insert is located on the internal annular seat of the second T-joint and the other end of the injector insert pipe has passed through the second T-joint and is located internal the hot water cylinder spaced apart from the top of the hot water cylinder; and connecting a pumped shower unit supply pipe to the second longitudinal port of the second T-joint.
(21) A method of retrofitting a pumped shower unit to a household vented hot water supply as claimed in claim 20 in which the step of disconnecting the vent pipe from the hot water cylinder further comprises cutting the vent pipe intermediate its ends; and the step of connecting a first longitudinal port of the second T-joint to the hot water cylinder further comprises connecting the first longitudinal port of the second T-joint to the part of the vent pipe still connected to the hot water cylinder.

-42(
22) A method of retrofitting a pumped shower unit to a household vented hot water supply as claimed in claim 21 comprising the additional step of setting the distance by which the end of the injector insert internal the hot water cylinder is to be spaced apart from the top of the hot water cylinder by selecting the appropriate length of vent pipe still to be connected to the hot water cylinder prior to cutting the vent pipe.
(23) A method of retrofitting a pumped shower unit to a household vented hot water supply as claimed in claim 20 in which the step of connecting a first longitudinal port of a second T-joint to the hot water cylinder further comprises the steps of: connecting one end of a spacer pipe directly to the hot water cylinder; connecting the other end of the spacer pipe directly to the first longitudinal port of the second T-joint, the spacer pipe thereby being located intermediate the hot water cylinder and the second T-joint.
(24) A method of retrofitting a pumped shower unit to a household vented hot water supply as claimed in claim 23 comprising the additional preliminary step of setting the distance by which the end of the injector insert internal the hot water cylinder is to be spaced apart from the top of the hot water cylinder by selecting an appropriate length of a spacer pipe.
(25) A household hot water installation comprising:

a vented hot water supply of the type comprising a hot water cylinder, a cold water supply tank located above the hot water cylinder and feeding cold water through a supply pipe to the bottom of the hot water cylinder, a vent pipe extending upwardly from the top of the hot water cylinder towards the cold water supply tank, a first T-joint connected in-line in the vent pipe and a hot water take-off pipe connected to the lateral port of the first T-joint and in fluid communication with the vent pipe for supply of hot water to one or more taps in the household; and a pumped shower unit including a pumped shower unit supply pipe;

-4320 a second T-joint comprising a first longitudinal port, a second longitudinal port and a lateral port; the first longitudinal port being connected to the hot water cylinder, the lateral port being connected to the vent pipe so that the

5 second T-joint is intermediate the vent pipe and the hot water cylinder, and the second longitudinal port being connected to the pumped shower unit supply pipe; and in which there is provided:

an injector insert of the type claimed in any of claims 1 to 19 inserted into

10 the second longitudinal port of the second T-joint, extending downwardly through second T-joint with the collar of the injector insert located on the internal annular seat of the second T-joint and the other end of the injector insert pipe having passed through the second T-joint and located internal the hot water cylinder spaced apart from the top of the hot water cylinder.
(26) A household hot water installation as claimed in claim 25 in which there is further provided a spacer pipe connected at one end to the first longitudinal port of the second T-joint and connected at its other end to the hot water cylinder, the spacer pipe thereby being located intermediate the hot water cylinder and the second T-joint.

-44(
27) A method of connecting a secondary return pipe to a hot water cylinder comprising the steps of:

connecting a first longitudinal port of a T-joint to the top of the hot water cylinder;

connecting a hot water supply pipe to a lateral port of the T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 downwardly into a second longitudinal port of the T-joint until the collar of the injector insert is located on the internal annular seat of the T-joint and the other end of the injector insert pipe has passed through the T-joint and is located internal the hot water cylinder spaced apart from the top of the hot water cylinder; and connecting the secondary return pipe to the second longitudinal port of the T-joint.
(28) A method of connecting a secondary return pipe as claimed in claim 27 in which the method comprises the step of connecting a spacer pipe intermediate the first longitudinal port of the T-joint and the hot water cylinder.
(29) A method as claimed in claim 28 in which the method comprises selecting the length of spacer to determine the distance by which the end of the other end of the injector insert is spaced apart from the top of the hot water cylinder.
(30) A household hot water installation of the type comprising:

a hot water cylinder;

a secondary return assembly including a flow pipe for delivering hot water from the hot water cylinder to at least one hot water outlet, a pump, and a secondary return pipe for circulating hot water between the hot water cylinder and the outlet;

-45the household hot water installation further comprising a T-joint for connecting the flow pipe and the secondary return pipe to the hot water cylinder, the T-joint having a first longitudinal port connected to the hot water cylinder, a lateral port connected to the flow pipe and a second longitudinal port connected to the secondary return pipe;

and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the T-joint, extending downwardly through the T-joint with the collar of the injector insert located on the internal annular seat of the T-joint and the other end of the injector insert pipe having passed through the T-joint and located internal the hot water cylinder spaced apart from the top of the hot water cylinder.
(31) A household hot water installation as claimed in claim 30 in which there is provided a spacer pipe intermediate the first longitudinal port of the T-joint and the hot water cylinder.
(32) A household hot water installation as claimed in claims 30 or 31 in which the injector insert is of the type in which the other end of the pipe is closed and in which there is provided an exhaust aperture in a side wall of the pipe adjacent to the closed end.

-46(
33) A method of connecting a secondary heat source supply pipe to a hot water cylinder configured to deliver hot water out through a hot water supply pipe at the top of the hot water cylinder, the method comprising the steps of:

connecting a first longitudinal port of a T-joint to the top of the hot water cylinder;

connecting the hot water supply pipe to a lateral port of the T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 downwardly into a second longitudinal port of the T-joint until the collar of the injector insert is located on the internal annular seat of the T-joint and the other end of the injector insert pipe has passed through the T-joint and is located internal the hot water cylinder spaced apart from the top of the hot water cylinder; and connecting the secondary heat source supply pipe to the second longitudinal port of the T-joint.
(34) A method of connecting a secondary heat source supply pipe to a hot water cylinder as claimed in claim 33 in which the method comprises the step of connecting a spacer pipe intermediate the first longitudinal port of the T-joint and the hot water cylinder.
(35) A method of connecting a secondary heat source supply pipe to a hot water cylinder as claimed in claim 33 or 34 in which the method comprises selecting the length of spacer to determine the distance by which the end of the other end of the injector insert is spaced apart from the top of the hot water cylinder.
(36) A household hot water installation of the type comprising:

a hot water cylinder;

-47a hot water supply pipe at the top of the hot water cylinder for delivering hot water from the hot water cylinder to at least one hot water outlet in the household;

a secondary heat source having a secondary heat source supply pipe to deliver water heated by the secondary heat source to the hot water cylinder;

the household hot water installation further comprising a T-joint for connecting the hot water supply pipe and the secondary heat source supply pipe to the hot water cylinder, the T-joint having a first longitudinal port connected to the hot water cylinder, a lateral port connected to the hot water supply pipe and a second longitudinal port connected to the secondary heat source supply pipe;

and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the T-joint, extending downwardly through the T-joint with the collar of the injector insert located on the internal annular seat of the T-joint and the other end of the injector insert pipe having passed through the T-joint and located internal the hot water cylinder spaced apart from the top of the hot water cylinder.
(37) A household hot water installation as claimed in claim 36 in which there is provided a spacer pipe intermediate the first longitudinal port of the T-joint and the hot water cylinder.
(38) A household hot water installation as claimed in claims 36 or 37 in which the injector insert is of the type in which the other end of the pipe is closed and in which there is provided an exhaust aperture in a side wall of the pipe adjacent to the closed end.

-48(
39) A household hot water installation as claimed in claims 36 to 38 in which the hot water cylinder has a cold water feed inlet adjacent the base of the hot water cylinder; and there is provided:

a cold water supply pipe for delivering cold water from a cold water source to the hot water cylinder through the cold water feed inlet;

a secondary heat source return pipe to deliver water from the hot water cylinder to the secondary heat source;

the household hot water installation further comprising a second T-joint for connecting the cold water supply pipe and the secondary heat source return pipe to the hot water cylinder;

the second T-joint having a first longitudinal port connected to the cold water feed inlet of the hot water cylinder, a lateral port connected to one of the cold water supply pipe and the secondary heat source return pipe, and a second longitudinal port connected to the other of the cold water supply pipe and the secondary heat source return pipe;

and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the second T-joint, extending inwardly through the second T-joint with the collar of the injector insert located on the internal annular seat of the second T-joint and the other end of the injector insert pipe having passed through the second T-joint and located internal the hot water cylinder.
(40) A household hot water installation as claimed in claim 39 in which the lateral port of the second T-joint is connected to the cold water supply pipe and the second longitudinal port of the second T-joint is connected to the secondary heat source return pipe.

-49(
41) A method of creating a bias in a piping network having a pair of fluid flow streams joining together into a single combined fluid flow stream using a T-joint, the method comprising the steps of:

connecting a first longitudinal port of the T-joint to an outlet pipe for the combined fluid flow stream;

connecting a lateral port of the T-joint to a first inlet pipe for one of the pair of fluid flow streams to be joined together;

inserting an injector insert into a second longitudinal port of the T-joint, the injector insert comprising an elongate length of pipe having an external diameter less than the internal diameter of the T-joint, the pipe having a collar at one end thereof dimensioned to engage and rest on an internal annular seat of the T-joint, and the pipe having a length so that the other open end of the pipe protrudes inwardly through the T-joint to a point beyond the central axis of the lateral port; and connecting the second longitudinal port of the T-joint to a second inlet pipe for the other of the pair of fluid flow streams to be joined together.
(42) An injector Tee comprising:

a standard T-joint having a first longitudinal port, a second longitudinal port and a lateral port; and an injector insert comprising an elongate length of pipe having an external diameter less than the internal diameter of the T-joint, the pipe having a collar at one end thereof dimensioned to engage and rest on an internal annular seat of the first longitudinal port of the T-joint, and the pipe having a length so that the other open end of the pipe protrudes inwardly through the T-joint to a point beyond the central axis of the lateral port.

-50(
43) An injector Tee as claimed in claim 42 in which the pipe has a length so that the other open end of the pipe protrudes inwardly through the T-joint to a point beyond the lateral port.
(44) An injector Tee as claimed in claim 43 in which the pipe has a length so that the other open end of the pipe protrudes inwardly through the T-joint and out through the second longitudinal port.
(45) An injector Tee as claimed in claims 42 to 44 in which the external diameter of the injector insert is less than or equal to 0.8 times the internal diameter of the Tjoint.
(46) An injector Tee as claimed in claims 42 to 44 in which the external diameter of the injector insert is less than or equal to 0.75 times the internal diameter of the T-joint.
(47) An injector Tee as claimed in claims 42 to 44 in which the external diameter of the injector insert is less than or equal to 0.70 times the internal diameter of the T-joint.
(48) An injector Tee as claimed in claims 42 to 47 in which the external diameter of the injector insert is greater than 0.3 times the internal diameter of the T-joint.
(49) An injector Tee as claimed in claims 42 to 47 in which the external diameter of the injector insert is greater than 0.5 times the internal diameter of the T-joint.
(50) An injector Tee as claimed in claims 42 to 47 in which the external diameter of the injector insert is greater than 0.6 times the internal diameter of the T-joint.
(51) An injector Tee as claimed in claims 42 to 50 in which the collar is frusto-conically shaped, splaying outwardly towards the open end.
(52) An injector Tee as claimed in claims 42 to 51 in which the collar is provided with an annular flange extending outwardly therefrom at its outermost end.

(53) An injector Tee as claimed in claim 42 to 52 in which the pipe has a circumferential weakened section intermediate its ends. 5 (54) An injector Tee as claimed in claim 42 to 53 in which the pipe has an external diameter of the order of between 0.0127m (½ inch) and 0.0203m (0.8 inch) and the collar has a maximum diameter of greater than 0.0254m (1 inch). (55) 10 An injector Tee as claimed in claim 42 to 53 in which the pipe has an external diameter of the order of between 0.009m (¾ inch) and 0.015m (³/₅ inch) and the collar has a maximum diameter of greater than 0.01905m (¾ inch). (56) An injector Tee as claimed in claim 42 to 53 in which the pipe has an external diameter of the order of between 0.014m and 0.022m and the collar has a 15 maximum diameter of greater than 0.028m. (57) An injector Tee as claimed in claim 42 to 53 in which the pipe has an external diameter of the order of between 0.011m and 0.018m and the collar has a maximum diameter of greater than 0.022m.

-52(58) A method of connecting both of a cold water supply pipe and a secondary heat source return pipe to the cold water feed inlet of a hot water cylinder adjacent the base of the hot water cylinder, the method comprising the steps of:

connecting a first longitudinal port of a T-joint to the cold feed inlet of the hot water cylinder;

connecting one of the cold water supply pipe and the secondary heat source return pipe to a lateral port of the T-joint;

inserting an injector insert of the type claimed in any of claims 1 to 19 into a second longitudinal port of the T-joint until the collar of the injector insert is located on the internal annular seat of the T-joint and the other end of the injector insert pipe has passed through the T-joint and is located internal the hot water cylinder; and connecting the other of the cold water supply pipe and the secondary heat source return pipe to the second longitudinal port of the T-joint.

(59) A household hot water installation of the type comprising:

a hot water cylinder having a cold water feed inlet adjacent the base of the hot water cylinder;

a cold water supply pipe for delivering cold water from a cold water source to the hot water cylinder through the cold water feed inlet;

a secondary heat source having a secondary heat source return pipe to deliver water from the hot water cylinder to the secondary heat source;

the household hot water installation further comprising a T-joint for connecting the cold water supply pipe and the secondary heat source return pipe to the hot water cylinder;

-53the T-joint having a first longitudinal port connected to the cold water feed inlet of the hot water cylinder, a lateral port connected to one of the cold water supply pipe and the secondary heat source return pipe, and a second longitudinal port connected to the other of the cold water supply

5 pipe and the secondary heat source return pipe;

and in which there is provided an injector insert of the type claimed in any of claims 1 to 19 inserted into the second longitudinal port of the T-joint, extending inwardly through the T-joint with the collar of the injector insert

10 located on the internal annular seat of the T-joint and the other end of the injector insert pipe having passed through the T-joint and located internal the hot water cylinder.

(60) A household hot water installation as claimed in claim 59 in which the lateral port 15 is connected to the cold water supply pipe and the second longitudinal port is connected to the secondary heat source return pipe.

Intellectual

Property

Office

GB1711334.1

1-60

Application No: Claims searched: