GB2541476A

GB2541476A - Plumbing connector having non-return valve

Info

Publication number: GB2541476A
Application number: GB1522290.4A
Authority: GB
Inventors: Winston Armstrong Russell
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-08-05
Filing date: 2015-12-17
Publication date: 2017-02-22
Anticipated expiration: 2035-12-17
Also published as: CA2937884A1; GB201513876D0; AU2016210670B2; GB201522290D0; GB2541476B; AU2016210670A1; EP3128087A2; EP3128087A3

Abstract

A plumbing connector comprises a chamber having an open upper chamber 262 and a lower chamber 282, an inlet connector 205 and an outlet connector 202 formed in a floor of the lower chamber 282 wherein the inlet connector 205 is supported above the open upper chamber by one or more arms 225. The upper chamber has an upper chamber floor 270 with an upper chamber outlet 275 having a non-return valve 242 which is arranged to open at a pre-selected pressure. A shield 204 is shaped to cover the open upper chamber 262. The valve 242 (Fig. 8) comprises a stem 340, a biasing member 355 for biasing the valve assembly into a closed position, a valve disc 345 for sealing the outlet and an upper washer 394 and a lower washer 395.

Description

PLUMBING CONNECTOR HAVING NON-RETURN VALVE

[001] The present invention relates to a plumbing device which allows a pressure and/or temperature relief valve for a high discharge fresh water system to be connected to a waste pipe or soil stack to provide a visible means of discharge and without the risk of back contamination and odours.

[002] An example of the use of a relief valve is with an unvented domestic hot water storage system (UVHWSS) or unvented hot water heater (UVHWH). Such a system typically has a temperature and/or pressure relief valve connected to a discharge pipe. The regulations for connection of the discharge pipe to a waste water system are strict because of the risk of back contamination from the pathogenic water in the waste water system to the fresh water in the storage system. Typically, the regulations require a tundish to provide a visible point of discharge and the outflow from the tundish to be connected in a particular way to discharge above an external ground floor gulley. Such a connection requires careful engineering and is expensive to install.

[003] In order to connect the vent valve to a soil stack within a building, arrangements need to be made to provide an odour trap to prevent any foul gases from the soil stack from entering the domestic location. On most domestic installations, a water trap would be used to prevent escape of gases and odours from the soil stack. Typically, a water trap comprises a bended tube in which water is trapped. A water trap allows passage of liquid and suspended solids but not gases. Generally speaking, a water trap is not suitable for use with a tundish as it will become ineffective through drying out. A water trap is also relatively bulky and is not suitable for use in all locations.

[004] A way of ameliorating these problems has been sought.

[005] According to the invention, there is provided a shielded connector which comprises a shield and a connector which comprises: a. a chamber having an open upper chamber and a lower chamber, b. an inlet connector and c. an outlet connector formed in a floor of the lower chamber wherein the inlet connector is supported above the open upper chamber by one or more arms; wherein the upper chamber has an upper chamber floor having an upper chamber outlet, the upper chamber is in fluid communication with the lower chamber by means of the upper chamber outlet; wherein the upper chamber outlet has a non-return valve which is arranged to open at a pre-selected pressure; wherein the lower chamber forms a flow conduit for receiving the valve when it is open; and wherein the shield is shaped to cover the open upper chamber.

[006] According to the invention, there is also provided a connector which comprises: a. a chamber having an open upper chamber and a lower chamber, b. an inlet connector and c. an outlet connector formed in a floor of the lower chamber wherein the inlet connector is supported above the open upper chamber by one or more arms; wherein the upper chamber has an upper chamber floor having an upper chamber outlet, the upper chamber is in fluid communication with the lower chamber by means of the upper chamber outlet; wherein the upper chamber outlet has a non-return valve which is arranged to open at a pre-selected pressure; wherein the lower chamber forms a flow conduit for receiving the valve when it is open.

[007] According to the invention, there is further provided a shield for a connector having an open upper chamber wherein the shield is shaped to cover the open upper chamber.

[008] According to the invention, there is also provided a valve assembly for use in sealing an outlet in a connector according to the invention wherein the valve assembly comprises a stem, a biasing member for biasing the valve assembly into a closed position, a valve disc for sealing the outlet, an upper washer and a lower washer wherein the upper and/or lower washer is shaped to support the valve disc such that the valve disc is not distorted in use. In some embodiments, the valve assembly additionally comprises an additional upper washer to provide extra support.

[009] In some embodiments, the upper and/or lower washers of the valve assembly are shaped to support the valve disc such that the valve disc is not compressed in use. It has been found that without the shaped upper and/or lower washer, the valve disc distorts such that the amount of water required to open the valve may change. In some embodiments, the upper and lower washers and the valve disc form central apertures for mounting on the valve stem; wherein one of the upper and lower washers forms a projection around its central aperture and wherein the valve disc aperture is shaped to receive the projection such that valve disc is supported by the upper and lower washers.

[0010] The advantages of the connector according to the invention include that as it is an adapted tundish, it is compact and space saving such that it can be used in a restricted location such as with an under counter water heater. Its simple construction enables it to have a rating for temperatures up to 100°C. Furthermore, by providing the lower chamber with a flow conduit for receiving the opened valve, the connector has an improved flow rate.

[0011] Further advantages include that the shield allows the connector to be used to vent a domestic boiler pressure relief valve to a waste water drain by preventing a user from inserting their fingers into the open upper chamber when the connector is in use. This is because the connector needs to be mounted on an outlet from the boiler which is visible but when it is in use, very hot water will be passed through the connector. Therefore the shield provides protection for a user from that water.

[0012] In some embodiments, the shield has a window such that water flow through the upper chamber can be observed. In some embodiments, the shield may be formed from a transparent material.

[0013] In some embodiments, the shield has a loose fit on the upper chamber such that the connector provides a vent to atmospheric pressure. In some embodiments, the shield has a tolerance fit (for example, a water tight fit) to the upper chamber wherein the shield has an outlet which provides the shielded connector with a vent to atmospheric pressure. In some embodiments, the connector and/or shield may have a rubber seal to minimise water spillage where the shield fits to the upper chamber.

[0014] In some embodiments, the flow conduit is formed by a wall which is spaced from the valve in use so as to provide a volume for liquid flow. In some embodiments, the flow conduit allows the valve to open sufficiently to allow a high flow of water. In some embodiments, a high flow rate of water is a flow rate of over 12 litres per minute, for example a flow rate of from 12 litres per minute, optionally from 15 litres per minute, optionally from 18 litres per minute to 30 litres per minute, optionally to 25 litres per minute, optionally to 18 litres per minute. In some embodiments, the connector according to the invention is suitable for use in venting an unvented boiler or cylinder, particularly a cylinder having high discharge characteristics such as a Megaflo (registered trademark) unvented cylinder or modern design unvented boilers.

[0015] In some embodiments, the lower chamberforms a first portion and the flow conduit wherein the first portion accommodates the upper chamber outlet and the valve when it is closed. In some embodiments, the first portion has a diameter which is greater than the diameter of the flow conduit such that there is a step between the first portion and the flow conduit. In some embodiments, the first portion has a diameter which is the same as the diameter of the flow conduit. In some embodiments, the floor of the lower chamber is a shelving floor. In some embodiments, the lower chamber floor is arranged between the flow conduit and the outlet connector.

[0016] In some embodiments, the pre-selected pressure is a pressure applied by a flow of liquid from the inlet such as may be produced by a pressure and/or temperature relief valve in operation. For example, the pre-selected pressure may be sufficiently high to prevent accidental opening of the non-return valve (for example due to dust or condensation on the valve) but not so high to restrict flow of liquid from the inlet such that liquid overflows from the open upper chamber. A skilled person would be able to determine a suitable pressure.

[0017] In some embodiments, the valve is a lift valve having a valve stem. In some embodiments, the upper chamber provides one or more ribs to support a valve guide for the valve stem. In some embodiments, the lift valve has a resilient member to bias it into a closed position. In some embodiments, the resilient member is arranged on the lift valve above the valve guide. Provision of a resilient member above the valve guide has the advantage of enabling the valve stem to be self-guiding such that only one valve guide is required.

[0018] The invention will now be illustrated with reference to the following Figures of the accompanying drawings which are not intended to limit the scope of the invention claimed: FIGURE 1 shows a schematic vertical cross-sectional view of an embodiment of the invention; FIGURE 2 shows a schematic overhead plan view of the embodiment of the invention; and FIGURE 3 shows a schematic horizontal cross-sectional view of the embodiment of the invention taken along line marked A-A' on Figure 1; FIGURE 4 shows a schematic vertical cross-sectional view of an embodiment of the shielded connector according to the invention; FIGURE 5 shows a schematic horizontal cross-sectional view of the embodiment of the invention taken along line marked B-B' on Figure 4; FIGURE 6 shows a cross-sectional view of a shield according to the invention; FIGURE 7 shows a schematic perspective view of the parts from which the shielded connector according to the invention are constructed; and FIGURE 8 shows a schematic perspective view of a valve assembly for use in the invention.

[0019] An embodiment of a connector according to the invention indicated generally at 100 is shown in Figures 1, 2 and 3. Connector 100 has an inlet 105, an upper chamber 162, a lower chamber 182 and a lift valve indicated at 142.

[0020] Inlet 105 is supported above upper chamber 162 by a pair of diametrically opposed arms 125 such that a vertical gap 107 is formed between the inlet and the upper chamber 162. Inlet 105 has an outer thread 110 for engaging with a tap connector (or other pipe fitting) and forms a tapered beak drip 115 which projects downwards into the vertical gap 107. Arms 125 are arranged so that horizontal gaps between the arms 125 and the vertical gap 107 are sufficient to provide an air break to drain, typical for a standard tundish.

[0021] Upper chamber 162 is shaped by circumferential upper chamber wall 165 and a shelving upper chamber floor 170. Upper chamber 162 has an open mouth for receiving liquid from the inlet. The upper chamber wall 165 supports arms 125. Upper chamber floor 170 forms upper chamber floor outlet 175 such that upper chamber floor 170 has an inverted truncated conical shape and such that the upper chamber floor 170 has a funnel shape for directing liquid to the upper chamber floor outlet 175. Upper chamber wall 165 has three inwardly projecting ribs 130 which support valve guide 135 which is arranged in the centre of the opening to upper chamber 162.

[0022] The lift valve 142 has the following components: a valve stem 140, a valve disc 145, a valve disc fixing 150, a valve spring 155 and a valve spring clip 160. The valve stem 140 is arranged to run through valve guide 135. At an upper part of the valve stem 140 above the valve guide 135, valve spring 155 is arranged on the valve stem 140 and secured to an upper end of the valve stem 140 by valve spring clip 160. At a lower end of the valve stem 140, the valve disc 145 is secured by valve disc fixing 150. Valve disc 145 is formed from a resilient material such as a plastics or rubber material, for example EPDM rubber. In an alternative embodiment, the valve spring 155 may be replaced by a suitable resilient member as would be known to a person of skill in the art.

[0023] The upper chamber floor outlet 175 forms a valve seat for lift valve 142 and which outlet 175 is normally closed by valve disc 145 which is biased by the valve spring 155 into that position. The valve spring 155 is arranged to open the lift valve 142 at a pre-selected pressure on the valve disc 145.

[0024] The lower chamber 182 has a ceiling 170, a first tubular lower chamber wall 180 forming a first lower chamber portion 180A, a horizontal step 181, a second lower chamber wall 183 forming a lower chamber flow conduit 183A, and a shelving lower chamber floor 185. The ceiling 170 of the lower chamber 182 is formed by the upper chamber floor 170. The first lower chamber portion 180A provides a cylindrical volume which receives or accommodates the upper chamber floor 170, upper chamber outlet 175 and valve 142 in its closed position, particularly valve disc 145 and valve disc fixing 150. In an alternative embodiment, instead of being cylindrical, first portion 180A may have a polygonal cross-sectional shape. The lower chamber flow conduit 183A provides a cylindrical volume 183A for receiving valve 142 in its open position, particularly valve disc 145, valve disc fixing 150 and part of valve stem 140. In an alternative embodiment, instead of being cylindrical, flow conduit 183A may have a polygonal cross-sectional shape. Lower chamber floor 185 shelves to form an opening for outlet 120 such that lower chamber floor 185 has an inverted truncated conical shape and such that the lower chamber floor 185 has a funnel shape for directing liquid to outlet 120. Outlet 120 has a tubular shape, a diameter suitable for attachment to a waste pipe and has a smooth outer surface suitable for engaging with a push fit or universal fitting (not shown).

[0025] The first lower chamber portion 180A provides a volume for receiving a liquid such as water discharged through the upper chamber floor outlet 175 when lift valve 142 is opened. Lower chamber flow conduit 183A has a smaller diameter than the first portion 180A because of step 181. In an alternative embodiment, the diameter of the flow conduit 183A may be the same as the diameter of the first portion 180A such that there is no step 181. The diameter of the flow conduit 183A is substantially greater than the diameter of the valve disc 145, for example 50% to 80% greater, particularly 66% greater such that a volume for liquid flow is provided between the lift valve 142 and the second lower chamber wall 183. When lift valve 142 is opened, flow conduit 183A receives lift valve 142 such that there is free flow of water around lift valve 142 within second lower chamber wall 183. If lower chamber 182 had the typical shape of a tundish, there would be no flow conduit 183A below first portion 180A but instead there would be a shelving floor. The insertion of the flow conduit 183A has surprisingly been found to increase flow rate of liquids through the connector 100 by 50% compared to the connector disclosed in GB2522634 but with only a 20% increase in the overall length of the connector 100 (the diameter of the connector 100 being the same as the diameter of the connector of GB2522634).

[0026] In an alternative embodiment, the diameter of valve disc 145 maybe less than that for outlet 120 such that the valve spring 155 and/or valve disc 145 may be replaced by removing valve spring clip 160, allowing the lift valve 142 to drop through outlet 120 and out of the connector 100 so that one or more of the components of lift valve 142 may be replaced.

[0027] An embodiment of a shielded connector according to the invention indicated generally at 200 is shown in Figures 4, 5 and 6. Shielded connector 200 has a connector 202 and a shield 204. Connector 202 comprises an inlet 205, an upper chamber 262, a lower chamber 282 and a lift valve indicated at 242.

[0028] Inlet 205 is supported above upper chamber 262 by a pair of diametrically opposed arms 225 such that a vertical gap 207 is formed between the inlet and the upper chamber 262. Inlet 205 has an outer thread 210 for engaging with a tap connector (or other pipe fitting). Arms 225 are arranged so that horizontal gaps between the arms 225 and the vertical gap 207 are sufficient to provide an air break to drain, typical for a standard tundish.

[0029] Upper chamber 262 is shaped by circumferential upper chamber wall 265 and a shelving upper chamber floor 270. Upper chamber 262 has an open mouth for receiving liquid from the inlet. The upper chamber wall 265 supports arms 225. Upper chamber floor 270 forms upper chamber floor outlet 275 such that upper chamber floor 270 has an inverted truncated conical shape and such that the upper chamber floor 270 has a funnel shape for directing liquid to the upper chamber floor outlet 275. Upper chamber wall 265 has three inwardly projecting ribs 230 which support valve guide 235 which is arranged in the centre of the opening to upper chamber 262.

[0030] The lift valve 242 has the following components: a valve stem in the form of a shoulder bolt 240, a valve disc 245, a valve disc fixing in the form of a self-locking nut 250 and a valve spring 255. The shoulder bolt 240 is arranged to run through valve guide 235. At an upper part of the shoulder bolt 240 above the valve guide 235, valve spring 255 is arranged on the valve shoulder bolt 240 and held in place at an upper end of the valve shoulder bolt 240 by a shoulder formation 260 on the valve shoulder bolt 240. At a lower end of the valve shoulder bolt 240, the valve disc 245 is secured by valve disc fixing 250. Valve disc 245 is formed from a resilient material such as a plastics or rubber material, for example EPDM rubber. In an alternative embodiment, the valve spring 255 may be replaced by a suitable resilient member as would be known to a person of skill in the art.

[0031] The upper chamber floor outlet 275 forms a valve seat for lift valve 242 and which outlet 275 is normally closed by valve disc 245 which is biased by the valve spring 255 into that position. The valve spring 255 is arranged to open the lift valve 242 at a pre-selected pressure on the valve disc 245.

[0032] The lower chamber 282 has a ceiling 270, a first tubular lower chamber wall 280 forming a first lower chamber portion 280A, a horizontal step 281, a second lower chamber wall 283 forming a lower chamber flow conduit 283A, and a shelving lower chamber floor 285. The ceiling 270 of the lower chamber 282 is formed by the upper chamber floor 270. The first lower chamber portion 280A provides a cylindrical volume which receives or accommodates the upper chamber floor 270, upper chamber outlet 275 and valve 242 in its closed position, particularly valve disc 245 and valve disc fixing 250. In an alternative embodiment, instead of being cylindrical, first portion 280A may have a polygonal cross-sectional shape. The lower chamber flow conduit 283A provides a cylindrical volume 283A for receiving valve 242 in its open position, particularly valve disc 245, valve disc fixing 250 and part of valve stem 240. In an alternative embodiment, instead of being cylindrical, flow conduit 283A may have a polygonal cross-sectional shape. Lower chamber floor 285 shelves to form an opening for outlet 220 such that lower chamber floor 285 has an inverted truncated conical shape and such that the lower chamber floor 285 has a funnel shape for directing liquid to outlet 220. Outlet 220 has a tubular shape 287, a diameter suitable for attachment to a waste pipe and has a smooth outer surface suitable for engaging with a push fit or universal fitting (not shown).

[0033] The first lower chamber portion 280A provides a volume for receiving a liquid such as water discharged through the upper chamber floor outlet 275 when lift valve 242 is opened. Lower chamber flow conduit 283A has a smaller diameter than the first portion 280A because of step 281. In an alternative embodiment, the diameter of the flow conduit 283A may be the same as the diameter of the first portion 280A such that there is no step 281. The diameter of the flow conduit 283A is substantially greater than the diameter of the valve disc 245, for example 50% to 80% greater, particularly 66% greater such that a volume for liquid flow is provided between the lift valve 242 and the second lower chamber wall 283. When lift valve 242 is opened, flow conduit 283A receives lift valve 242 such that there is free flow of water around lift valve 242 within second lower chamber wall 283. If lower chamber 282 had the typical shape of a tundish, there would be no flow conduit 283A below first portion 280A but instead there would be a shelving floor. The insertion of the flow conduit 283A has surprisingly been found to increase flow rate of liquids through the connector 200 by 50% compared to the connector disclosed in GB2522634 but with only a 20% increase in the overall length of the connector 200 (the diameter of the connector 200 being the same as the diameter of the connector of GB2522634). The increase in overall length of the connector 100,200 being to provide the connector with a push fit facility. Without the push fit connection, the length of the connector 100,200 would be substantially the same as that disclosed in GB2522634.

[0034] In an alternative embodiment, the diameter of valve disc 245 may be less than that for outlet 220 such that the valve spring 255 and/or valve disc 245 may be replaced by removing self locking nut 250, allowing shoulder bolt 240 and valve spring 255 to drop through inlet 205 and out of the connector 200 so that one or more of the components of lift valve 242 may be replaced.

[0035] As shown in Figure 6, shield 104 has a frustroconical shape having an upper opening 101 which is shaped to fit over inlet 105 and a skirt 103 which is shaped to cover 162 and has a length approximately the same as the length of arms 125.

[0036] A further embodiment of the shielded connector according to the invention is indicated generally at 300 in Figure 7. The shielded connector 300 has a shield 304 and a connector 302. Figure 7 illustrates the five parts from which the connector 302 is constructed are shown. The five parts are the upper chamber head 390, the upper chamber body 391, the upper chamber foot 392, the lower chamber body 393 and the valve assembly 396. The four parts 390,391,392,393, may be joined together by ultrasonic welding or, in an alternate embodiment, by an equivalent technique as might be known to a person of skill in the art. The upper chamber head 390 comprises two circular plastic rings 310,312 which are joined by arms 325. Upper ring 310 is smaller in diameter than lower ring 312 and forms inlet 305 such that upper ring 310 is arranged concentrically above lower ring 312 by arms 325. Upper chamber body 391 comprises an outer circular plastic ring formed by upper chamber wall 365, inwardly projecting ribs 330 mounted on an inner surface of upper chamber wall 365 and valve guide 335 which is supported by ribs 330. The upper chamber foot 392 provides the upper chamber floor 370 and upper chamber floor outlet 375. The lower chamber body 393 provides the lower chamber 382 as described above for the second embodiment. The valve assembly 396 provides the lift valve 342. Valve assembly 396 is shown in more detail in Figure 8. Valve assembly 396 comprises a valve stem 340 in the form of a shoulder bolt, a valve disc 345, a valve disc fixing 350 in the form of a self-locking nut, a valve spring 355, a first upper washer 397, a second upper washer 394 and a lower washer 395. The second upper washer 394 has an inverted top hat shape forming a lower projection 394A. Valve disc 345 has a central aperture 345A which is shaped to receive not only the shaft of shoulder bolt 340 but also lower projection 394A such that in use, valve disc 345 is supported by second upper washer 394 and lower washer 395 such that the shape of valve disc 345 is not distorted when valve disc fixing 350 is tightened on shoulder bolt 340. Additionally first upper washer 397 provides additional support by preventing second upper washer 394 from being pushed up past the shoulder of the threaded portion of the valve stem 340. The inclusion of separate first upper washer 397 provides a washer function on an upper side of valve disc 345, allowing second upper washer 394 to provide only a supporting function for the valve disc 345. In an alternative embodiment, the first and second upper washers 394,397 might be arranged below the valve disc 345.

Claims

1. A connector which comprises: a. a chamber having an open upper chamber and a lower chamber, b. an inlet connector and c. an outlet connector formed in a floor of the lower chamber wherein the inlet connector is supported above the open upper chamber by one or more arms; wherein the upper chamber has an upper chamber floor having an upper chamber outlet; wherein the upper chamber is in fluid communication with the lower chamber by means of the upper chamber outlet; wherein the upper chamber outlet has a non-return valve which is arranged to open at a pre-selected pressure; and wherein the lower chamber forms a flow conduit for receiving the valve when it is open.

2. A connector as defined in Claim 1 wherein the valve is a lift valve.

3. A connector as defined in Claim 2 wherein the valve is a lift valve having a valve stem.

4. A connector as defined in Claim 3 wherein the upper chamber provides one or more ribs to support a valve guide for the valve stem.

5. A connector as defined in Claim 3 or Claim 4 wherein the lift valve has a resilient member to bias it into a closed position.

6. A connector as defined in Claim 5 wherein the resilient member is arranged on the lift valve above the valve guide.

7. A connector as defined in any one of the preceding Claims wherein the flow conduit is formed by a wall which is spaced from the valve in use so as to provide a volume for liquid flow.

8. A connector as defined in any one of the preceding Claims wherein the flow conduit allows the valve to open sufficiently to allow a high flow of water.

9. A connector as defined in Claim 8 wherein a high flow of water is a flow rate of over 12 litres per minute.

10. A connector as defined in any one of the preceding Claims wherein the valve has a valve disc and where the diameter of the flow conduit is 50% to 80% greater than the diameter of the valve disc.

11. A connector as defined in any one of the preceding Claims wherein the lower chamber forms a first portion for accommodating the upper chamber outlet and the valve when it is closed and the flow conduit.

12. A connector as defined in Claim 11 wherein the first portion has a diameter which is greater than the diameter of the flow conduit such that there is a step between the first portion and the flow conduit.

13. A connector as defined in Claim 11 wherein the first portion has a diameter which is the same as the diameter of the flow conduit.

14. A connector as defined in any one of the preceding Claims wherein the floor of the lower chamber is a shelving floor.

15. A connector as defined in any one of the preceding Claims wherein the lower chamber floor is arranged between the flow conduit and the outlet connector.

16. A shielded connector comprising a shield and a connector as defined in any one of the preceding Claims wherein the shield is shaped to cover the open upper chamber.

17. A shielded connector as defined in Claim 16 wherein the shield has a window such that water flow through the upper chamber can be observed.

18. A shielded connector as defined in Claim 16 or Claim 17 wherein the shield is formed from a transparent material.

19. A shielded connector as defined in any one of Claims 16 to 18 wherein the shield has a loose fit on the upper chamber such that the connector provides a vent to atmospheric pressure.

20. A shielded connector as defined in any one of Claims 16 to 18 wherein the shield has a tolerance fit to the upper chamber; and wherein the shield has an outlet which provides the shielded connector with a vent to atmospheric pressure.

21. A shield for use with a connector as defined in any one of Claims 1 to 15 wherein the shield is shaped to cover the open upper chamber of the connector wherein the shield is as defined in any one of Claims 16 to 20.

22. A valve assembly for use in sealing an outlet in a connector as defined in any one of Claims 1 to 15 wherein the valve assembly comprises a stem, a biasing member for biasing the valve assembly into a closed position, a valve disc for sealing the outlet, an upper washer and a lower washer wherein the upper and lower washers support the valve disc such that the valve disc does not distort in use.

23. A valve assembly as defined in Claim 22 wherein the upper and lower washers of the valve assembly support the valve disc such that it does not contact the valve stem.

24. A valve assembly as defined in Claim 22 or Claim 23 wherein the upper and lower washers and the valve disc form central apertures for mounting on the valve stem; wherein one of the upper and lower washers forms a projection around its central aperture and wherein the valve disc aperture is shaped to receive the projection such that valve disc is supported by the upper and lower washers.

25. A connector as defined in any one of Claims 1 to 15 or a shielded connector as defined in any one of Claims 16 to 20 which comprises a valve assembly as defined in any one of Claims 22 to 24.

26. A connector, shielded connector, shield and/or valve assembly substantially as hereinbefore described or illustrated with reference to the Figures of the accompanying drawings.