GB2442008A - Dosing vessel for sealed central heating system - Google Patents

Abstract

A container for adding a chemical such as an inhibitor to a pressurized central heating system has a wide mouthed vessel to which the chemical can be added, and a screw cap with two fluid connections. One of the connections is attached to the filling loop of the heating system, whilst the other is connected, via a flexible hose, to a mains water supply. When the valves are opened, mains water mixes with the chemical and forces it into the heating system.

Description

I

Central Heating Dosing Vessel This invention relates to a water propelled chemical dosing vessel designed to be used on domestic sealed type central heating systems (e.g. combi boilers).

Heating systems require chemicals such as rust inhibitors, cleansers and descalers etc to ensure their long life, efficient operation and to comply with manufacturers warranties. When a domestic sealed type central heating system is newly installed or drained down for maintenance, for example the exchanging of a radiator or pump, chemicals need to be added. At present a radiator valve or a blanking cap is often removed to allow liquid to be either, poured in using a funnel, forced in using a garden sprayer or disposable aerosol cans or injected in using a cartridge and gun. These methods are either expensive or time consuming, special fittings, adapters, tools, dust sheets and cloths etc have to be found, there is also the added risk of spillage and associated claims for damage to floor coverings. When working on old heating systems where a fitting has to be disconnected to administer chemicals, it can cause extra problems if the joint does not reseal, resulting in further time delays.

To overcome these problems, the present invention proposes that a portable dosing vessel, designed to withstand pressure could be used, in combination with our registered screw cap design and some fittings. The dosing vessel can easily be attached to most domestic sealed type central heating systems via the boiler filling loop valve connections. When the valves are opened the flow of mains water pressure enters the vessel, and mixes with the chemicals using our plunge pool method', the solution is then forced into the central heating system.

It is a unique and cost effective way to add chemicals to domestic condensing combination boiler heating systems these are classed as being sealed types'.

The dosing vessel will save the user time, it's quick, very easy to use and clean, chemicals can be added in minutes, it may also lower the risk of spillage and associated insurance claims, the only tools required will be a pair of pipe grips! Preferably the vessel will feature, (a) a maximum volume of between 1.25 to 1.50 litres.

(b) a wide closure/cap! making it easier to pour liquids in, with low risk of spillage.

(c) the ability to withstand a hydraulic test pressure of at least 4 bar (60psi).

(d) a screw thread designed for heavy duty that will expand under pressure and yet still form a seal using a rubber type o' ring.

(e) an injection moulded construction from any plastic such as polypropylene or high density polyethylene etc. z Preferably the closure will feature, (a) a wider screw cap as compared to a bottle, so that fluid ports can be moulded on for fittings to screw into, there would also need to be enough space to get to the fitting connections easily with your fingers, or a spanner.

(b) the ability to withstand a hydraulic test pressure of at least 4 bar (6Opsi).

(C) a screw thread designed for heavy duty that will expand under pressure and yet still form a seal using a rubber type a' ring.

(d) an injection moulded construction from any plastic such as polypropylene etc. (e) resistance to low impact damage, such as being dropped onto the floor.

(f) practicality and be aesthetically pleasing and interesting to the eye.

(g) a silicon hose fitted to the base of the cap, this helps the mixing process.

Preferably the hose will feature, (a) thumb turn wing nuts on each end of the flexible braided stainless steel sheathed rubber hose, so it can be easily connected and disconnected. It will also have male o' ring spigots pressed onto each end that will fit inside the fitting on the cap and inside any of the two valves.

(b) the ability to withstand a hydraulic test pressure of at least 4 bar (6Opsi).

(c) the ability to resist kinking, thus restricting flow, the circular shape was chosen to help prevent this and make carrying and hanging the unit in between use as practical as possible.

(d) materials that have anti corrosion properties.

Preferably the fittings screwed into the closure will feature, (a) the ability to withstand a hydraulic test pressure of at least 4 bar (6Opsi).

(b) anti corrosion properties such as brass, treated/plated steel or any plastic such as polypropylene.

(C) resistance to low impact damage, such as being dropped onto the floor.

The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1.

Shows the cap (8) unscrewed and removed from the vessel (7) and the chemical solution (10) is being added, the cap is then replaced to be hand tight.

Figure 2.

Shows the blanking cap (1) removed from the non return valve (4) the filling loop hose (5) supplied with the dosing vessel (7) is connected from the vessel (any side) to the non return valve (4) on the central heating return pipe, the system has been drained and is now empty, the pressure gauge (II) is at 0 bar, all draining off points, and radiator bleed valves can be sealed ready for filling up.

Figure 3.

Shows the blanking cap (1) removed on the cold water inlet valve (2) and the hose supplied with the boiler (3) is connected from the vessel at fitting (9) to the cold water inlet valve (2). Valves (2) and (4) are opened and the solution is flushed through into the central heating system, the water from the mains supply enters the vessel (7) and mixes with the solution, this travels up tube (6) and mixes further inside the central heating system, the system is filled until the pressure gauge (11) reads approximately 0.5 bar, then the valves are turned off.

Figure 4.

Shows the dosing vessel disconnected, and the boiler filling loop (3) connected from the non return valve (4) on the central heating return pipe to the cold water inlet valve (2). Valves (2) and (4) are opened to fill up the central heating system and all radiators are bled of air, the system is filled till the gauge (11) is reading 1 bar (normal operating pressure). The cold water inlet valve (2) and the non return valve (4) must be closed, then the filling loop hose (3) can be disconnected, the blanking caps (1) are then refitted back to each valve and tightened, the job is now complete and the system has been dosed.

A further description of the four main components that form the Dosing Vessel' 1. The Flexible Hose This is a standard type combination boiler filling-loop hose. It is manufactured from high pressure specification flexible rubber pipe and wrapped with a flexible, stainless steel braided protective covering. Identical fittings are then crimp pressed onto each end of the hose, these are the thumb turn wing nut type 1/2 bsp nut fittings with a male o' ringed spigot. The hose connects to the brass/plastic male nipple fittings on the plastic/polypropylene cap, and to one of the filling loop valves to form a watertight joint. The hose could be made from flexible plastics, rubber, silicone, reinforced polyester or nylon etc. 2. The Fittings Two brass/plastic screw type threaded 1/2 bsp nipple fittings screw into the top of the closure and are sealed by o' ring rubber type seals, or washers made from nylon/rubber/teflon etc. The protruding part of the fitting is also threaded to allow the filling loop hose to screw onto it The internal diameter is the exact size to form a seal by the o' ring on the hose spigot, that enters into the inside of the brass/plastic nipple fitting. These fittings could also take the form of the push fit type o' ring seal designs made from any type of plastic.

3. The Closure The closure/cap is a registered design and can be manufactured from any type of plastic, such as polypropylene or polyethylene and incorporates either an o' ring seal or a flat rubber/neoprene/teflon seal with a heavy duty internal thread to match the external thread of the vessel, this is made slightly larger to enable movement of the screw cap, it forms an engineered leak proof seal under pressure and expansion. There are also two % bsp threaded holes that lead into the top of the vessel, they allow water to enter in and out of the vessel. One of the ports has a spout inside the vessel, where a rubber hose pushes on, this is designed to create better mixing during the flushing process, these two internally threaded holes or ports have chamfered faces on their outside periphery to allow a rubber o' ring to seal on the mating face of the cap to fitting joint.

4. The Vessel The design of the vessel/jar/bottle is special it has a wide screw type top/closure and its shape, material and thickness have been developed to ensure it will withstand pressures exceeding 4 bar (60 psi). It could be moulded from any plastic such as polypropylene, polyethylene or high density polyethylene and will hold 1.25 litres. The patented thread design allows the screw cap/closure and vessel/jarbottle to expand under pressure whilst still forming a watertight joint.

(This vessel is already manufactured in the UK, the company have kindly sent me their thread specification, so we could design and mould the closure).

Claims (6)

1. Claims 1.

   A portable dosing vessel with a wide male screw thread type closure is used in combination with our registered cap design with identical female screw thread compatibility, comprising attachment means, for attaching the unit to the two filling loop valve connections as found on a typical sealed type domestic central heating systems, whereby water pressure and flow are used as the motive force to mix and flush out any chemical solution poured into the vessel, through and into the central heating system, the unit can then be disconnected, all components must be able to withstand a pressure safety test of 4 bar (6Opsi) and resist failure.
2. 2.

   A portable dosing vessel according to claim 1, in which the means of attaching the unit is by using any type of flexible hose including the standard combination boiler filling loop, typically made from high pressure rubber with a braided stainless steel protective sheathing, and half inch British Standard Pipe female fittings with male o' ring spigots on both ends
3. 3.

   A portable dosing vessel according to claim 1, in which the maximum volume of the vessel is less than 2 litres capacity.
4. 4.

   A portable dosing vessel according to claim 1, in which the chemical mixing, flushing and dosing process is propelled solely by using the mains' cold water supply to the building.
5. 5.

   A portable dosing vessel according to claim 4, in which the chemical solution administered to the vessel will be mixed in a way similar to our plunge pool method' as shown in drawing 3, on page
6. 6.