GB2448707A

GB2448707A - Discharge valve assembly

Info

Publication number: GB2448707A
Application number: GB0707895A
Authority: GB
Inventors: David Bailey; Ian Wilson
Original assignee: Fort Valve Engineering Ltd
Current assignee: Fort Valve Engineering Ltd
Priority date: 2007-04-24
Filing date: 2007-04-24
Publication date: 2008-10-29
Also published as: WO2008129329A1; GB0707895D0

Abstract

A discharge valve assembly has a valve housing 10, an inlet 12, an outlet 14 and a flow passage 11 extending between the inlet and the outlet. A shut-off valve 24 is mounted on the housing 10 adjacent the inlet 12, and a flow control valve 110 is mounted on the housing 10 adjacent the outlet 14. The shut-off valve 24 is displaceable in the upstream direction to an open position via a pivoting arm 36. Actuating means (48, Fig. 1) is located externally of the valve body and is connected to a shaft 46 located externally of the flow passage 11 for pivoting the arm 36. The arm 36 is connected to the valve closure member 22 only on its downstream side and extends through an aperture 40 in the wall of the flow passage located downstream of the valve seat 28.

Description

1 2448707

DESCRIIPTION

VALVE ASSEMBLY

The present invention relates to valve assemblies and in particular, but not exclusively, to valve assemblies for use with ISO tank containers.

ISO tank containers are vessels which are used for the transport of liquids and gases in bulk. The fluid container itself is usually a cylindrical tank which fits within a cuboidal supporting framework of standard dimensions and having standard connecting sockets at its corners, so that the unit can be manoeuvred, secured and transported using standardised equipment.

One of the safety requirements of ISO tank containers is that the tank outlet must be provided with two valves, a first control valve for controlling the flow of fluid from the tank and a second shut-off valve which can be closed very rapidly in the event of an emergency or malfunction. It is the practice to connect the shut-off valve to the tank outlet and interconnect the control valve to the outlet of the shut-off valve. While this gives a very satisfactory performance and satisfies safety requirements, the size of the two valves in combination is very large. As a consequence, the space available for the tank within the confines of a standard ISO tank container framework is reduced, thereby reducing the maximum volume of tank which can fit within the framework.

It is an aim of the present invention to reduce the amount of space occupied by the two valves so that the maximum volume available for a tank within the confines of an ISO tank container framework is increased.

Co-pending United Kingdom patent application 0624653.2 discloses a valve assembly in the form of a valve housing having an inlet, an outlet, and a flow passage extending between the inlet and the outlet.

First and second valves are mounted on the housing adjacent the inlet and outlet respectively for controlling the flow of fluid through the flow passage.

Whilst the valve in that patent application works extremely well for most products, it will be noted that the valve located adjacent to the inlet of the valve assembly is biased towards a closed position by means of a spring located on the upstream side of the valve closure member. The spring and its associated support are therefore in contact with the contents of the container tank. This can cause problems if, for example, the product within the tank is corrosive, since the spring and its associated support are in continuous contact with the contents. In addition, if the contents of the tank are relatively viscous, there can be an increased tendency for the product to build up in the vicinity of the spring area, which can result in the valve closure member being inadvertently held open or closed.

It is an aim of the present invention to reduce the amount of space occupied by the two valves of the prior art, whilst overcoming or alleviating the problems associated with the valve assembly in co-pending application 0624653.2.

In accordance with the present invention, a discharge valve assembly comprises a valve housing having an inlet, an outlet and a flow passage extending between the inlet and outlet, first and second valves mounted on the valve housing adjacent to the inlet and the outlet respectively for controlling the flow of fluid through the flow passage, the valve adjacent to the inlet being displaceable in the upstream direction in an opening direction and comprising a shaft pivotally mounted and located externally of the flow passage, actuating means located externally of the valve body and connected to the shaft for pivoting the latter and an arm connected to the shaft and connecting to the valve closure member only on its downstream side, the arm extending through an aperture in the wall of the flow passage located downstream of the valve seat.

In such a valve assembly the only item which might restrict the flow of material through the valve located adjacent to the inlet, other than the valve closure member, is the arm. In particular, the shaft on which the arm is mounted is isolated from the interior of the valve and thus will not become contaminated during normal use. Also, the relatively few components in the flow path through the valve adjacent to the inlet results in an increased rate of discharge, and this is enhanced by the reduced turbulence resulting from the small number of components in the flow path through the valve. The valve adjacent to the inlet is also easy to clean, since only a few components are exposed to the material flowing through it. The opening of the valve closure member in the upstream direction of the valve located adjacent to the inlet also helps to dislodge any material which may have set or partially set in the vicinity of the valve. Also, the valve located adjacent to the inlet is easier to service since, for example, a seal on the valve closure member may be replaced without the need to dismantle the whole of the valve.

Preferably, when the valve adjacent to the inlet is displaced to its open position, it projects out of the valve housing.

The assembly may further comprise a bore within the material forming the valve body, within which the shaft is pivotally located.

Preferably, the discharge valve assembly further comprises a spring acting upon the shaft to urge the valve closure member towards the closed position.

The spring preferably comprises a torsion spring.

Preferably, the torsion spring is located around the shaft.

The spring may be located in a bore within the material forming the valve body.

Preferably, the discharge valve assembly comprises sealing means for isolating the spring from the material being discharged through the valve.

The discharge valve assembly may further comprise means for retaining the valve closure member in the open position.

The actuating means preferably comprises a handle connected to the shaft.

The handle may be connected to the shaft by means of a plurality of linkages.

Preferably, the linkages are pivotally connected.

Preferably, the valve adjacent to the outlet comprises a pivotally mounted valve closure member.

Preferably, the valve ciosure member is generally circular in shape.

In one embodiment, the valve inlet is circular.

The valve outlet may be elliptical.

Preferably, the valve closure member is releasably securable to the arm.

Preferably, the valve body is provided with a planar face for abutment with a fluid container.

The valve body may comprise two parallel planar faces.

The valve seat is preferably located between the valve inlet and the valve outlet.

Preferably, one of the first and second valves comprises a valve closure member mounted on the valve housing and releasably engageable with a valve seat, the valve seat being formed on the valve housing.

Preferably, one of the first and second valves comprises a valve closure member mounted on the valve housing and releasably engageable with a valve seat which is formed separately from the valve housing, the assembly further comprising means for attaching the valve seat to the valve housing.

Each of the first and second valves may comprise a valve closure member engageable with a valve seat, the valve closure members being mounted on the valve housing.

One of the first and second valves may comprise a valve seat formed on the valve housing.

One of the first and second valves may comprise a valve seat which is formed separately from the valve housing, the assembly further comprising means for attaching the valve seat to the valve housing.

Preferably, the other of the first and second valves is located adjacent to the outlet.

Preferably, one of the first and second valves comprises a shut-off valve.

Preferably, the other of the first and second valves comprises a regulating valve.

The regulating valve may comprise a butterfly valve.

The butterfly valve is preferably angularly displaceable through an obtuse angle.

Preferably, the valve closure member is angularly displaceable through an angle whereby the normally innermost face of the face closure member faces downstream.

Preferably, the valve closure member is displaceable through an angle of approximately 1600.

The discharge valve assembly may comprise means for temporarily securing the regulating valve in a predetermined position and preferably comprises means for temporarily securing the regulating valve in one of a plurality of predetermined positions.

Preferably, the flow passage is elongate.

Preferably, the cross-sectional area of the flow passage is larger at the outlet than at the inlet.

The valve assembly may further comprise connection means for connecting the valve housing to the outlet of a source of fluid whose flow is to be controlled.

The connection means may comprise a connection flange.

Preferably, at least one of the first and second valves is operable manually.

The at least one manually operable valve may be operated by means of a handle.

Preferably, both of the first and second valves are operable manually, e.g. by means of a handle.

By way of example only, a specific embodiment of the present invention will now be described, with reference to the accompanying drawings, in which:-Fig. 1 is a perspective view of an embodiment of valve assembly in accordance with the present invention; Fig. 2 is a side view of the valve assembly of Fig. 1; Fig. 3 is a plan view of the valve assembly of Fig. 1; Fig. 4 is a longitudinal cross-section through the valve assembly of Fig. 1; Fig. 5 is a further longitudinal cross-section through the valve assembly of Fig. 1, looking in the direction of arrows V-V in Fig. 2, with both valves of the assembly in the fully open position; and Fig. 6 is an exploded perspective view of the valve assembly of Fig. 1.

The accompanying drawings illustrate a valve assembly which is particularly suitable for connection to the outlet port of an ISO container tank for discharging liquid and gaseous products from the container tank.

The valve assembly comprises an elongate main valve housing 10 which has an elongate flow passage 11 which increases in cross-sectional area from an inlet end 12 to an outlet end 14. The inlet end 12 is provided with an annular mounting flange 16 which is welded at annular weld 17 to the main valve body portion. The flange 16 has eight equally-angularly spaced apertures 18, by means of which the valve assembly is secured to a corresponding mounting flange (not shown) around the discharge port of an ISO tank container. As illustrated in the drawings, the mounting flange 16 is inclined to the longitudinal axis of the main valve housing 10 to fit the flange on the ISO tank container.

Radially inwardly of the mounting flange 16, the main valve housing 10 is formed into a frusto-conical valve seat 20 which is sealingly engageable with a first valve closure member 22 which forms part of a shut-off valve 24 mounted on the valve housing adjacent the inlet 12. The valve closure member 22 comprises a circular metal disc having a peripheral groove 26 which receives an 0-ring seal in the form of an encapsulated PTFE seal 28 which is engageable with the valve seat 20.

The valve closure member 22 is generally disc-like in construction with a protruding central boss 30 and its maximum diameter is greater than that of the annular valve seat 20. The 0-ring seal 28 projects partially beyond the valve closure member 22, whereby it is engageable with the valve seat 20.

The central boss 30 of the valve closure member comprises a projecting shank portion 32 of reduced diameter and an enlarged head 34 by means of which the valve closure member 22 is securable to a pivotally mounted crank arm 36, as will be explained. One end of the crank arm 36 is provided with two forked portions 38 which are adapted to pass one either side of the reduced diameter shank portion 32 on the valve closure member 22. The valve closure member 22 is securely attached to the crank arm by means of a pin 41 which passes through two aligned apertures in the ends of the two forked portions 38. The underside of the enlarged head 34 of the boss 30 and the part of the forked portions 38 in contact therewith are both part-spherical to permit some small degree of movement. The securing pin 38 may be withdrawn when the valve is in the open position to allow the valve closure member to be removed in order to allow the seal to be replaced.

As best seen in Figs. 4 and 5, the crank arm 36 is bent and passes through a rectangular aperture 40 in the wall of the valve flow passage 11 adjacent to the inlet end 12. The inner end of the crank arm 36 is provided with an internally splined annular head portion 42 which is located over a complementarily splined portion 44 of an actuating shaft 46 which extends perpendicularly to the crank arm 36. One end of the shaft 46 passes through a first tubular housing 47 which projects outward from, and forms part of, the valve body. One end of the shaft 46 projects out of the end of the first spring housing and is connected to an actuating handle 48. The other end of the shaft 46 extends into a second tubular housing 50 projecting outwardly from, and forming part of, the main portion of the valve body.

The portion of the shaft 46 extending towards the actuating handle 48 passes through a bore in the first tubular housing 47 and the shaft is provided with a portion 54 of enlarged diameter which is of substantially the same diameter as the bore and which retains the rod in alignment with the bore. A wear and retaining assembly 56 comprising bushes, a washer and a split pin is located on one end of the shaft 46.

The actuating lever 48 is not connected directly to the shaft 46 but instead is connected by means of a linkage 80. In particular, the actuating lever 48 is pivotally mounted on a lug 82 extending rearwardly of the mounting flange 16. The actuating lever is also secured to one end of a first link arm 84. The opposite end of the first link arm 84 is pivotally mounted to one end of a second link arm 86. The opposite end of the second link arm is in turn pivotally mounted to one end of a third link arm 88. The opposite end of the third link arm 88 is formed into an internally splined annular head 90 which engages with a complementarily-splined protruding portion 92 of the shaft 46, the two being secured together by means of the wear and retaining assembly 56. Rotation of the actuating lever 48 thereby causes rotation of the shaft 46 via the linkage 80 and thereby causes the valve closure member 22 to be lifted from its valve seat.

The end of the shaft 46 remote from the actuating handle 48 is received within a spring assembly 100 comprising an elongate torsion spring 101, one end of which is welded to an internally splined bush 102, the other end of which is welded to a mounting plate 104. The spring 101 and bush 102 are located in a spring mounting tube 98 which forms part of the housing of the valve assembly. An externally splined end portion 96 of the shaft 46 is received in the internally-splined bush 102 and thus rotates with it. The spring is pretensioned by means of a bolt head 106 formed on the outer face of the mounting flange 104 and when the appropriate tension has been applied, the mounting flange 104 is secured to the projecting end of the spring mounted tube 98 by means of two bolts 108 passing through threaded apertures in the end of the spring housing 98.

The spring assembly 100 thereby biases the valve closure member 22 towards engagement with the valve seat 22. A high tension is usually applied to the spring so that the valve closure member 22 snaps shut very quickly.

The shaft 46 is sealed with respect to the first tubular housing 47 and the spring mounting tube 98 by means of a sealing assembly 94 whose components fit onto the shaft 46. Specifically, seals and b fit onto the shaft 46 on the end nearer the handle 48 and bushes c, ci and e and seals f and g fit onto the opposite end of the shaft 46.

A flow control valve in the form of a butterfly valve, indicated generally at 110, is also mounted on the main valve housing 10 adjacent the outlet 14. The butterfly valve 110 comprises a circular disc-shaped valve closure member 112 engageable with an annular valve seat member 114. The upstream side of the valve closure member 112 of the butterfly valve is provided with a first annular mounting lug 116 which receives a stub shaft 118 which is pivotally received in a bearing 120 located in a recess 122 of the main valve housing 10. A second annular lug 124 on the upstream side of the valve closure member is internally splined and receives a splined end connection 126 of an actuating shaft 128 which passes sealingly through a tubular extension 130 of the main valve housing 10 which extends perpendicularly to the longitudinal direction of the main valve housing 10. The outer end of the actuating shaft 128 is also provided with a splined portion 132 by means of which it is connected to an actuating handle 134 which extends perpendicularly to the actuating shaft 128. The handle 134 also carries an operating lever 136. The lever 136 is pivotally mounted on the handle 134 and by squeezing the lever with respect to the handle, the lever lifts a handle locating pin 138 which is receivable in one of two recesses 140a, 140b in a locating flange 142 extending perpendicularly to the tubular extension 130, by means of which the handle and the valve closure member 112 of the butterfly valve 110 may be retained in a desired one of two extreme positions, open and closed, at right angles to each other. The pin 138 is biased towards the locating flange 142 and the recesses 140a, 140b therein (downwards as seen in Fig. 6) by means of a compression spring 144. The pin projects through a hole 146 in the handle and may alternatively be withdrawn from the recesses 140a, 140b by means of a ring 148 which passes through a diametrically extending hole in the upper end of the pin 138.

A flat security lug 150 projects from the portion of the handle adjacent to the actuating shaft 128 and a second planar security lug 152 projects from the locating flange 142. The lugs 150,152 are positioned adjacent to each other when the valve closure member 112 is in a closed position, which allows a security seal (not shown) to be passed through aligned apertures 154a, 154b in the lugs 150, 152.

The valve closure member 112 of the butterfly valve is engageable with the annular valve seat member 114. The annular valve seat member 114 is received in a complementarily-shaped annular recess 156 at the outlet end of the main valve housing 10 and is retained in position by means of a retaining coupling 158 having a central circular elongate passage 160 which corresponds to the aperture of the valve seat member 114 and having a peripheral flange 162 with four bolt-receiving apertures 164 for receipt of retaining bolts 166 which pass through the apertures into corresponding apertures 168 in a retaining flange 170 at the outlet end 14 of the main valve housing 10 and which are retained by means of nuts 172. The outer end of the retaining coupling 158 is also provided with an externally-threaded tubular neck portion 174 which is adapted to screw-threadedly receive an internally threaded end cap 176 which closes off the valve assembly from the exterior when it is not in use.

In use, the end cap 176 is firstly unscrewed. The butterfly valve 110 is then opened by squeezing the operating lever 136, which causes the spring-loaded locating pin 138 to be withdrawn from its associated aperture 140a. The handle 134 of the butterfly valve 110 can then be pivoted through a right angle in order to open the butterfly valve.

The lever is released, which allows the spring-loaded locating pin 138 to engage in the other aperture 140b, thereby retaining the butterfly valve in the open position.

The shut-off valve 24 is then opened by rotating the handle 48 in the anti-clockwise direction (as seen in Fig. 2). As explained previously, rotation of the handle 48 results in rotation of the shaft 46 via the linkage 80, thereby lifting the valve closure member 22 from the valve seat 20 and opening the shut-off valve. The linkage 80 has an over-centre action, whereby the valve closure member is retained in its fully opened position until the valve is manually closed. Fluid is thereby allowed to pass firstly through the shut-off valve 24 and then through the butterfly valve 110 and out of the valve assembly.

It should be noted that the only item which might restrict the flow of material through the shut-off valve 24, other than the valve closure member 22, is the crank arm 36. In particular, the spring 100 and the actuating shaft 46 on which the crank arm is mounted are isolated from the interior of the shut-off valve 24 and thus will not become contaminated during normal use. Also, the relatively few components in the flow path through the shut-off valve 24 results in an increased rate of discharge, and this is enhanced by the reduced turbulence resulting from the small number of components in the flow path through the shut-off valve. The shut-off valve 24 is also easy to clean, since only a few components are exposed to the material flowing through it. The opening of the valve closure member 22 in the upstream direction of the shut-off valve 24 also helps to dislodge any material which may have set or partially set in the vicinity of the valve. Also, the shut-off valve 24 is easier to service since, for example, the seal 28 on the valve closure member 22 may be replaced without the need to dismantle the whole of the shut-off valve 24.

When it is desired to stop the flow of fluid, the shut-off valve 24 is firstly closed by rotating the handle 48 of the valve in the clockwise direction (as illustrated in Fig. 2). The biasing of the spring 100 of the shut-off valve ensures that the shut-off valve closes very quickly. The flow of fluid through the main valve housing 10 has ceased, the butterfly valve is then closed by squeezing the operating lever 136, which withdraws the spring-loaded locating pin 138 from its associated aperture 140b, and pivoting the handle 134 through a right angle so that the butterfly valve closure member 112 assumes a closed position with respect to the annular valve seat member 114. The lever 136 is then released, which allows the spring-loaded locating pin 138 to engage the first recess 140a, thereby securing the butterfly valve in its closed position. If the valve assembly is not to be used for some time thereafter, the end cap 176 is then screwed onto the externally-threaded tubular neck portion 174.

Claims

1. A discharge valve assembly comprising a valve housing having an inlet, an outlet and a flow passage extending between the inlet and outlet, first and second valves mounted on the valve housing adjacent to the inlet and the outlet respectively for controlling the flow of fluid through the flow passage, the valve adjacent to the inlet being displaceable in the upstream direction in an opening direction and comprising a shaft pivotally mounted and located externally of the flow passage, actuating means located externally of the valve body and connected to the shaft for pivoting the latter and an arm connected to the shaft and connecting to the valve closure member only on its downstream side, the arm extending through an aperture in the wall of the flow passage located downstream of the valve seat.

2. A discharge valve assembly as claimed in claim 1, wherein when the valve adjacent to the inlet is displaced to its open position, it projects out of the valve housing.

3. A discharge valve assembly as claimed in claim I or claim 2, further comprising a bore within the material forming the valve body, within which the shaft is pivotally located.

4. A discharge valve assembly as claimed in any of the preceding claims, further comprising a spring acting upon the shaft to urge the valve closure member towards the closed position.

5. A discharge valve assembly as claimed in claim 4, wherein the spring comprises a torsion spring.

6. A discharge valve assembly as claimed in claim 5, wherein the torsion spring is located around the shaft.

7. A discharge valve assembly as claimed in any of claims 4 to 6, wherein the spring is located in a bore within the material forming the valve body.

8. A discharge valve assembly as claimed in claim 7, comprising sealing means for isolating the spring from the material being discharged through the valve.

9. A discharge valve assembly as claimed in any of the preceding claims, further comprising means for retaining the valve closure member in the open position.

10. A discharge valve assembly as claimed in any of the preceding claims, wherein the actuating means comprises a handle connected to the shaft.

11. A discharge valve assembly as claimed in claim 10, wherein the handle is connected to the shaft by means of a plurality of linkages.

12. A discharge valve assembly as claimed in claim 11, wherein the linkages are pivotally connected.

13. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve adjacent to the outlet comprises a pivotally mounted valve closure member.

14. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve closure member is generally circular in shape.

15. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve inlet is circular.

16. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve outlet is elliptical.

17. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve closure member is releasably securable to the arm.

18. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve body is provided with a planar face for abutment with a fluid container.

19. A discharge valve assembly as claimed in claim 18, wherein the valve body comprises two parallel planar faces.

20. A discharge valve assembly as claimed in any of the preceding claims, wherein the valve seat is located between the valve inlet and the valve outlet.

21. A discharge valve assembly as claimed in any of the preceding claims, wherein one of the first and second valves comprises a valve closure member mounted on the valve housing and releasably engageable with a valve seat, the valve seat being formed on the valve housing.

22. A discharge valve assembly as claimed in any of the preceding claims, wherein one of the first and second valves comprises a valve closure member mounted on the valve housing and releasably engageable with a valve seat which is formed separately from the valve housing, the assembly further comprising means for attaching the valve seat to the valve housing.

23. A discharge valve assembly as claimed in any of the preceding claims, wherein each of the first and second valves comprises a valve closure member engageable with a valve seat, the valve closure members being mounted on the valve housing.

24. A discharge valve assembly as claimed in claim 23, wherein one of the first and second valves comprises a valve seat formed on the valve housing.

25. A discharge valve assembly as claimed in claim 23 or claim 24, wherein one of the first and second valves comprises a valve seat which is formed separately from the valve housing, the assembly further comprising means for attaching the valve seat to the valve housing.

26. A discharge valve assembly as claimed in any of the preceding claims, wherein the other of the first and second valves is located adjacent to the outlet.

27. A discharge valve assembly as claimed in any of the preceding claims, wherein one of the first and second valves comprises a shut-off valve.

28. A discharge valve assembly as claimed in any of the preceding claims, wherein one of the first and second valves comprises a regulating valve.

29. A discharge valve assembly as claimed in claim 28, wherein the regulating valve comprises a butterfly valve.

30. A discharge valve assembly as claimed in claim 29, wherein the butterfly valve is angularly displaceable through an obtuse angle.

31. A discharge valve assembly as claimed in claim 29 or claim 30, wherein the valve closure member is angularly displaceable through an angle whereby the normally innermost face of the face closure member faces downstream.

32. A discharge valve assembly as claimed in claim 30 or claim 31, wherein the valve closure member is displaceable through an angle of approximately 160 .

33. A discharge valve assembly as claimed in any of claims 28 to 32, comprising means for temporarily securing the regulating valve in a predetermined position.

34. A discharge valve assembly as claimed in claim 33, comprising means for temporarily securing the regulating valve in one of a plurality of predetermined positions.

35. A discharge valve assembly as claimed in any of the preceding claims, wherein the flow passage is elongate.

36. A discharge valve assembly as claimed in claim 35, wherein the cross-sectional area of the flow passage is larger at the outlet than at the inlet.

37. A discharge valve assembly as claimed in any of the preceding claims, further comprising connection means for connecting the valve housing to the outlet of a source of fluid whose flow is to be controlled.

38. A discharge valve assembly as claimed in claim 37, wherein the connection means comprises a connection flange.

39. A discharge valve assembly as claimed in any of the preceding claims, wherein at least one of the first and second valves is operable manually.

40. A discharge valve assembly as claimed in claim 39, wherein said at least one manually operable valve is operated by means of a handle.

41. A discharge valve assembly as claimed in claim 39 or claim 40, wherein both of the first and second valves are operable manually.

42. A discharge valve assembly as claimed in claim 41, wherein both of the first and second manually operable valves are operated by means of a handle.

43. A discharge valve assembly substantially as herein described with reference to, and as illustrated in, the accompanying drawings.