GB2376290A

GB2376290A - A filling means for a pressurised fluid system such as a central heating system

Info

Publication number: GB2376290A
Application number: GB0109512A
Authority: GB
Inventors: Robert Glyn Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-18
Filing date: 2001-04-18
Publication date: 2002-12-11
Anticipated expiration: 2021-04-18
Also published as: GB0109512D0; GB2376290B

Abstract

A filling means for a pressurised fluid system whereby the filling means comprises three sections, an inlet 11, an intermediate 12 and an outlet 13. A fluid supply passes through a first and second valve 17, 18 which are disposed between the sections for the control of the fluid from one section to the other. These valves are operably controlled by a pressure sensor 23 located in the pressurised fluid system 16. The intermediate section also includes an exhaust with a third valve 19 which allows the supply fluid to pass there through, and preferably this valve also responds to the pressure sensor. A delay means could be incorporated so that the second valve will operate after the first valve at a pre selected time delay. An air vent 22 may be disposed in the intermediate section to allow expulsion of air from within this section. Double and single check valves 20, 21 may be located in the inlet and outlet sections, respectively. Preferably the first and second valves are electrically operable normally closed/power open valves, where as the third valve is normally open/power closed. The fluid system could be a central heating system whereby the fluid supply is mains water.

Description

PATENTS ACT 1977 A10261GB-JNL Title: Filling Means Description of Invention This invention relates to a filling means for a pressurised fluid system, and particularly but not exclusively to a filling means of a sealed central heating system.

Wet central heating systems contain contaminated water which for safety reasons must be kept separate from potable drinking water. By law, drinking water and central heating water must not be allowed to mix, especially while the system is being used or topped up. There are many types of wet central heating systems, but all use water either through evaporation or leakage and the water loss to evaporation or leakage must be replaced. In a traditional open vented central heating system, the system is topped up from a tank fitted at the highest point in the system. Water loss through evaporation or leakage is replaced by water from the tank which fills the system by gravity. The tank is kept topped up by a float valve. A natural air gap is created between the float valve and the water level which prevents cross contamination.

In more modem systems, the systems are sealed and pressurised. To top up the system, conventionally a temporary hose connection to a water supply is used. When the system has been filled to a desired pressure the temporary hose connection has to be removed to maintain the air gap. Due to the fluid pressure in the system, the system will gradually lose water through joints. For safety reasons, boilers will not work at low pressure and so when low pressure is detected, the system will cease to function. When this happens, the system must be manually recharged as described above.

An aim of the invention is to provide a new or improved filling means for a pressurised fluid system.

According to a first aspect of the invention, we provide a filling means comprising an inlet section for connection to a fluid supply, an outlet section

If'--i c,-rt ; r% n rr-. nnpe-ti-ri hptxxjppn for connection to said system and an intermediate section connected between uiL LI% Jll LM actl ayaL---ttl""I.. . L........

I said inlet section and said outlet section, a sensor means responsive to fluid pressure in the system, first valve means operable to permit fluid to pass from the inlet section to the intermediate section, and second valve means operable to permit fluid to pass from the intermediate section to the outlet section, the first valve means and second valve means being responsive to the sensor means, an exhaust and third valve means operable to permit fluid to pass from the intermediate section to the exhaust.

The third valve means may be responsive to the sensor means.

The sensor means may be operable in response to the fluid pressure in the pressurised fluid system falling below a first pre-selected pressure to operate the first valve means to permit fluid to flow from the inlet section to the intermediate section and to operate the second valve means to permit fluid to pass from the intermediate section to the outlet section.

The sensor means may be responsive to the fluid pressure of the system falling below the first pre-selected pressure to operate to the third valve means to prevent passage of fluid from the intermediate section to the exhaust.

The filling means may comprise delay means whereby operation of the second valve occurs at a pre-selected time after operation of the first valve means.

The sensor means may be responsive to fluid pressure in the system exceeding a second pre-selected pressure greater than the first pre-selected pressure to operate the first valve means to prevent fluid flow from the inlet section to the intermediate section and to operate the second valve means to prevent fluid flow from the intermediate section to the outlet section.

The sensor means may be responsive to the fluid pressure in the system exceeding the second pre-selected pressure to operate the third valve means to permit fluid to pass from the intermediate section to the exhaust.

The sensor means may be responsive to the pressure falling below a third pre-selected pressure less than the first pre-selected pressure to operate the first valve means and second valve means to prevent passage of fluid from the inlet section to the intermediate section and from the intermediate section to the outlet section.

The filling means may comprise an air vent valve which may permit expulsion of air from the intermediate section.

A double check valve may be provided in the inlet section.

A single check valve may be provided in the outlet section.

The first valve means and the second valve means may comprise electrically operable nOlmally c1osed/power open valves.

The third valve means may comprise an electrically operable normally open/power close valve.

According to a second aspect of the invention, we provide a pressurised fluid system which comprises a filling means according to the first aspect of the invention.

The pressurised fluid system may be a central heating system and the fluid may comprise water.

The fluid supply may comprise a mains water supply.

The invention will now be described by way of example only with reference to the accompanying drawings wherein : Figure 1 shows a filling means according to the present operation in diagrammatic form in a first mode of operation Figure la shows a first alternative configuration of the sensor means of Figure 1.

Figure Ib shows a second alternative configuration of the sensor means of Figure 1.

Figure 2 shows the fining means of figürc 1 in a second mode of operation, Figure 3 shows the filling means of figure 1 in a third mode of operation, and Figure 4 shows the filling means of figure 1 in a fourth mode of operation.

Referring to the drawings, a filling means is generally indicated at 10.

The filling means comprises an inlet section 11, an intermediate section 12 and an outlet section 13. The inlet section 11, intermediate section 12 and outlet section 13 comprise pipes or ducts of any appropriate desired type. The filling means 10 further comprises an exhaust 14 whereby fluid from the filling means may be permitted to pass to a drain or other suitable outlet. The inlet section 11 is adapted to be connected at an inlet 15 to a pressurised fluid supply, and at an outlet 16 being provided in the outlet section 13 for connection to a pressurised fluid system such as a sealed central heating system. The pressurised fluid supply preferably comprises a mains water supply.

Connected between the inlet section 11 and the intermediate section 12 is a first valve means 17. A second valve means 18 is similarly connected between the intermediate section 12 and the outlet section 13. A third valve means 19 is connected between the intermediate section 12 and the exhaust 14. In the present example, the first valve means 17 and second valve means 18 comprise electrically operable nonna1Jy closed/power open valves, and the third valve means 19 comprises an electrically operable normally open/power close valve.

FUl1her provided in the inlet section II is a double check valve 20 of conventional type, operable to allow fluid to flow in only one direction, in the present example from the inlet 15 to the first valve means 17.

A shock arrester Ha is preferably provided connected to the inlet section 11 between the double check valve 20 and the first valve means 17.

The shock arrester Ha, of conventional type, is provided to reduce or prevent shudder of the pipes due to the action of the first valve means I I generating shocks which are transmitted through the fluid. A single check valve 21 is provided in the outlet section 3 to prevent fluid flowing in the direction from the outlet 16 towards the second valve means 18.

An automatic air vent valve 22 is further provided connected to the highest point of the intermediate section 12. The air vent valve 22 is of conventional type and permits the expulsion of air from the intermediate section 12 whilst preventing the passage of fluid.

The filling means further comprises a sensor means generally indicated at 23. The sensor means is connected by a live terminal 24 to a live terminal 25 of an electrical supply. The sensor means 23 is connected on line 26 to the first valve means 17 and the third valve means 19. Connected between the line 26 and the second valve means 18 is an electrical line 27 in which is connected a delay means 28, in the present example a five second time delay resistor. The first valve means 17, second valve means 18 and third valve means 19 are all connected by electrical line 29 to a neutral terminal 30 connected to a neutral terminal 31 of an electrical supply. A resettable meter 26a is provided connected to line 26 to record the number of times the filling means is activated. When the pressurised fluid system and/or the filling means 10 is serviced, the number of times the filling means 10 has been activated can be checked in order to ascertain, for example, whether the pressurised fluid system

is suffering from consistent or repeated leaks for example allowing intermittent or slow leaks to be identified.

The sensor means 23 is operable to connect the line 26 to the terminal 24 as follows. First, the sensor means 23 is responsive to the pressure of the fluid in the pressurised fluid system falling below a first pre-selected pressure,

in the present example 1. 0 bar, at which pressure it is desired to supply pressure from the pressurised fluid supply to the pressurised fluid system. The sensor means 23 is responsive to the fluid pressure in the system exceeding a second pre-selected pressure greater than the first pre-selected pressure, in the present example 1.8 bar to interrupt the electrical connection between terminal 24 and line 26 to prevent the further supply of fluid from the pressurised fluid supply to the pressurised fluid system. Thirdly, the sensor means 23 in the present example is responsive to the pressure of the fluid in the system falling below a third pre-selected pressure which is less than the first pre-selected pressure, in the present example 0.5 bar, to prevent any electrical connection between the terminal 24 and line 26. When the pressure falls below the third pre-selected pressure, it is taken as an indication that there is a catastrophic failure in the pressurised fluid system, and so the sensor means 23 prevents further supply of fluid from the pressurised fluid source to the pressurised fluid system.

The sensor means 23 may comprise any appropriate configuration of components as desired. Two possible alternative configurations are described with reference to Figures la and Ib, although it will be appreciated that a filling

means according to the present invention will not be limited to the particular configurations shown in Figures If ! and 112.

Refening now to Figures la and lb, the sensor means 23 is shown in more detail. In each alternative, the sensor means 23 comprises a first sensor element 32, 32', a second sensor element 33, 33' and a third sensor element 34, 34'. Each sensor element 32, 32', 33, 33', 34, 34' is suitably connected to the outlet section 13 to respond to the fluid pressure therein. Each sensor element further comprises three terminals, a common connection labelled C, a break-onrise connection labelled B and a make-on-rise connection labelled M. The common connection C is always connected either to the break-on-rise connection B or the make-on-rise connection M. Each sensor element 32, 32',

33,33', 34, 34'is responsive to the pressure in the outlet section 13 passing a pre-determined value to change the connection of the common connection C either to the make-on-rise connection M on the break-on-rise connection B.

The sensor elements 32, 32', 33, 33', 34, 34'may be selected such that the sensor element only switches as a result of the pressure in the outlet section 13 rising past a selected pressure, or if the pressure rises or falls past the same pre- selected pressure, or further alternatively that the sensor element has a pressure differential such that a switch occurs at a first pressure when the pressure rises and at a second, different pressure when the pressure is falls.

Referring now to Figure la, the terminal 24 is connected to the common connection C of the third sensor element 34. The make-on-rise connection M of the third sensor element 34 is connected to the common connection C of the first sensor element 32, the break-on-rise connection B of which is connected to the make-on-rise connection M of the second sensor element 33. The common connection C of the second sensor element 33 is connected to the line 26. In this example, the third sensor element 34 is responsive to the pressure falling below the third pre-selected pressure to break the connection between the make-on-rise connection M and common connection C. The first sensor element 32 is set such that the connection between common connection C and the break-on-rise connection B is made only when the pressure in the outlet section 13 falls below the first pre-selected pressure. The first sensor element 32 thus maintains a connection between the common connection C and makeon-rise connection B even when the pressure then subsequently rises past the first pre-selected pressure. The second sensor element 33 is responsive to the pressure in the outlet section 13 to maintain the connection between C and M when the pressure is below the second pre-selected pressure, and break the connection when the pressure is above the second pre-selected pressure.

In the alternative of Figure Ib, the configuration is different in that the first pressure element 32'is responsive to the pressure in the outlet section 30 passing the first and second pre-seiected pressures. The break-on-rise connection B of the first sensor element 32 is connected to the common connection C of the second sensor element 33', the break-on-rise connection B of which is connected to the line 26. In this example, the second sensor element 33'comprises a high pressure cut-out which cuts out when the pressure in the outlet section 13 exceeds a fourth pre-selected pressure greater than the second pre-selected pressure. The pressure sensor 32'is selected or adjusted such that the break-on-rise connection B is connected to the common connection C when the pressure falls below the first pre-selected pressure, and connects the make on rise connection M to the common connection C when the pressure in the outlet section 3 rises above the second pre-selected pressure.

The first sensor element 32'thus exhibits hysteresis.

The filling means operates as follows. When the fluid pressure in the system is within an acceptable range, as shown in Figure I, then in a first mode of operation there is no electrical connection between terminal 24 and line 26 via the sensor means 23. The first valve means 17 and the second valve means 18 are in their closed positions, and the third valve means is in its open position. In this situation, the intermediate section 12 is connected to the exhaust 14 via the third valve 9. The intermediate section 12 is thus free of fluid, and hence maintains a required air gap between the pressurised fluid system and the pressurised fluid supply.

When the pressure in the system falls below the first pre-selected

pressure, this is detected by the sensor means 23, in the examples of Figures la and lb by the first sensor element 32. 32'. In a second mode of operation, the sensor means 23 connects the power line 26 to the terminal 24. The third valve means 19 is closed and the first valve means is moved to its open position. The intermediate section 12 thus begins to fill with fluid from the fluid supply via

the inlet section 11. As the intermediate section 12 fills with fluid, air is vented from the intermediate section 12 via the automatic air vent valve 22 as shown in Figure 2. Once a pre-set time period has elapsed, set by the delay means 28, the second valve means 18 then opens. As shown in Figure 3, in a third mode of operation fluid is thus supplied from the supply via the inlet section 11, intermediate section 12 and outlet section 13 to the pressurised fluid system. The single check valve 21 ensures that there is no back flow from the pressurised fluid system in the direction of the fluid supply.

The delay between operation of the first valve means 17 and the second valve means 18 also ensures that all air is expelled from the intermediate section 12, thus preventing or reducing the undesirable introduction of air into the pressurised fluid system.

The fluid pressure in the system then increases until it reaches a second selected pressure, in the present example 1. 8 bar. This is detected by the sensor means 23, in the example of Figure la by the second sensor element 33 and in the example of Figure 112 by the first sensor element 32'. In a fourth mode of operation, the sensor means 23 then interrupts the electrical connection between the terminal 24 and line 26. The first valve means 17 and second valve means 18 move to their closed positions, and the third valve means 19 moves to its open position. Fluid flow between the inlet section 11 and intermediate section 12 and the intermediate section 12 and the outlet section 13 is thus prevented. The fluid in the intermediate section 12 is permitted to flow via the third valve means) 9 to the exhaust 14 as illustrated in Figure 4. The filling means then returns to the first mode of operation as shown in Figure 1.

In the event of a catastrophic failure in the pressurised fluid system, it would be possible for the fluid pressure in the pressurised fluid system to fall below the first pre-selected pressure and remain below the second pre-selected pressure such that the filling means then would maintain the connection

between the fluid supply and the pressurised fluid system. To overcome this problem, if the fluid pressure in the pressurised fluid system falls below a third

11'I 1. 1. 1 1 1 r : 1,. 1 h pre-selected pressure which is ! ess thai) the lirst pre-se ! ected pressurC, the sensor means 23 interrupts the connection between line 26 and the terminal 24.

The first valve means 17 and the second valve means 18 thus remain in their closed positions even though the fluid pressure in the pressurised fluid system is below both the first pre-selected pressure and the second pre-selected pressure. This will hence prevent the continued supply of fluid to the pressurised fluid system in the event of a serious leak. In the examples of Figures la and lb, the third sensor element 34, 34'responds to the pressure falling below the third pre-selected pressure to break the connection.

The filling means as described herein is primarily intended to be used in connection with sealed central heating systems which are supplied with pressurised water and to facilitate the automatic topping up of such systems with water from the mains water supply. However, it will be apparent that such a system may be used in any other appropriate application where any other appropriate fluid will be used. The system as described herein may be assembled using conventional known components and as such any appropriate components may be used as desired.

In the present specification "comprise" means "includes or consists of" and"comprising"means"includingorconsistingof".

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result. as appropriate, may, separately, or in any combination of such features. be utilised for realising the invention in diverse forms thereof.

Claims

1. A filling means for a pressurised fluid system, the filling means comprising ; an inlet section for connection to a fluid supply, an outlet section for connection to said system and an intermediate section connected between said inlet section and said outlet section, a sensor means responsive to fluid pressure in the system, first valve means operable to permit fluid to pass from the inlet section to the intermediate section, and second valve means operable to permit fluid to pass from the intermediate section to the outlet section, the first valve means and second valve means being responsive to the sensor means, an exhaust, and third valve means operable to permit fluid to pass from the intermediate section to the exhaust.

2. A filling means according to claim I wherein the third valve means is responsive to the sensor means.

3. A filling means according to claim 1 or claim 2 wherein the sensor means is operable in response to the fluid pressure in the pressurised fluid system falling below a first pre-selected pressure to operate the first valve means to permit fluid to flow from the inlet section to the intermediate section and to operate the second valve means to permit fluid to pass from the intermediate section to the outlet section.

4. A filling means according to claim 3 where dependant on claim 2 wherein the sensor means is responsive to the fluid pressure of the system

falling below the first pre-selected pressure to operate to the third valve means laUUI ! ; Ut : IUW LIlt : 111 : :'1 VI t ; - : :, t : It : l-It : U pi t : : :' : :'UI C ; IV VpCl all ; ; IV lIlC 11111 U val VC 111Call : > to prevent passage of fluid from the intermediate section to the exhaust.

5. A filling means according to claim 3 or claim 4 comprising delay means 0 whereby operation of the second valve means occurs at a pre-selected time after operation of the first valve means.

6. A filling means according to any one of claims 3 to 5 wherein the sensor means is responsive to the fluid pressure in said system exceeding a second pre-selected pressure greater than the first pre-selected pressure to operate the first valve means to prevent fluid flow from the inlet section to the intermediate section and to operate the second valve means to prevent fluid flow from the intermediate section to the outlet section.

7. A filling means according to claim 6 wherein the sensor means is z : I responsive to the fluid pressure in the system exceeding the second pre-selected pressure to operate the third valve means to permit fluid to pass from the intermediate section to the exhaust.

8. A filling means according to any one of claims 3 to 7 wherein the sensor means is responsive to the pressure falling below a third pre-selected pressure less than the first pre-selected pressure to operate the first valve means and second valve means to prevent passage of fluid from the inlet section to the intermediate section and from the intermediate section to the outlet section.

9. A filling means according to any one of the preceding claims wherein an air vent valve is provided to permit expulsion of air from the intermediate section.

10. A filling means according to any one of the preceding claims wherein a double check valve is provided in the inlet section.

11. A filling means according to any one of the preceding claims wherein a single check valve is provided in the outlet section.

12. A filling means according to any one of the preceding claims wherein the first valve means and the second valve means comprise electrically operable normally closed/power open valves.

13. A filling means according to any one of the preceding claims wherein the third valve means comprises an electrically operable normally open/power closed valve.

14. A filling means substantially as described herein and/or in the accompanying drawings.

15. A pressurised fluid system comprising a filling means according to any one of the preceding claims.

16. A pressurised fluid system according to claim 15 wherein the system is a central heating system and the fluid comprises water.

17. A pressurised fluid system according to claim 16 wherein the fluid supply comprises a mains water supply.

18. A system substantially as described herein and/or with reference to the accompanying drawings.

19. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.