GB2263155A - Check valve assembly - Google Patents

Abstract

A check valve assembly for use in testing, bleeding or injection in fluid systems and especially for use in conjunction with a primary valve such as a gate valve comprises first and second check valves (2, 3) each including a poppet member (5) movable between closed and open positions in a valve casing (7, 8), the assembly being adapted to receive an operating tool (Fig. 3, not shown) especially in the form of a stinger, for opening the valves. For setting the valve assembly in the open position, the poppet member (5) of the first valve (2) when moved by the operating tool causes an opening movement of the poppet member (5) of the second valve (3). A closure cap (4) is fitted to the valve assembly in the out-of-use condition and replaces the operating tool. In a preferred embodiment, the poppet member (5) of each valve co-operates with a sleeve (10) to provide a controlled flow path (10A, 10C, 10B) for fluid through the valve assembly in the valve open position. <IMAGE>

Description

CHECK VALVE ASSEMBLAGE The present invention relates to a check valve device.

Check valves are known and serve a number of functions, for example for testing, bleeding or injection, especially in conjunction with a primary valve such as a gate valve.

It is an object of the present invention to provide an improved check valve which is versatile in its application.

According to the present invention a check valve assemblage comprises first and second check valves each including an openable valve member, and means for the fitting of an operating tool for the valves, the arrangement being such that movement of the valve member of the first valve causes an opening movement of the valve member of the second valve. Preferably the valves are in the form of poppet valves, spring means being provided to urge the valves to a closure posiion.

Preferably the valve assembly includes a valve body provided with external seal means, to enable the device to be sealingly fitted in a casing wall for example. In particular the valve body can include external thread means to enable the body to be screw threaded into threaded bore positions, and a resilient seal can be provided between the body and the casing wall.

Preferably the operating tool includes a body provided with a screw thread enabling the tool body to be screw threaded to the valve body portion of the first check valve, and the tool preferably includes an actuating rod located in a bore in the tool body operatively engagable with the valve member of the first valve.

Preferably said screw thread of the tool body corresponds to said internal thread of the valve body whereby the tool may be screw threaded directly to said threaded bore portion. The tool body preferably includes port means for fluid ducting of the check valves.

Preferably limiting means are provided to limit the possible opening movement of the check valves, these means comprising for example a head on the actuator rod and a corresponding seating in the tool body. The present invention is also a check valve assemblage including a check valve of poppet type, and an operating tool for said check valve of removable stinger form, said tool including port means for the check valve. The arrangement is preferably such that, with the tool removed, a closure cap can be fitted conveniently to the check valve to place the valve in a sealed out-of-use condition.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Fig. 1 shows a sectional side view of the external check valve of a check valve assemblage in accordance with the present invention; Fig. 2 shows a similar view of the internal valve of the assemblage; Fig. 3 shows a sectional side view of an operating tool for the check valve assemblage; and Fig. 4 shows the poppet valve of the external and internal valves to a larger scale, and in the "open" position.

Referring to the drawings, a check valve device for location in a casing wall 1 is in the form of an assembly comprising a first, or external, check valve 2, (Fig. 1) and a second, internal or buried, check valve 3 (Fig. 2). The assembly is intended for use in primary valves, for example in gate valves, and simply by way of example can have the following uses: (a) Testing of metal to metal seals e.g. in ports.

(b) Allowing bleeding down of areas prior to a maintenance operation, to provide safety.

(c) Allowing injection of lubricant (e.g. grease) for lubrication purposes.

The valve assembly 2/3 seals both internally and externally and is intended to seal both gases and liquids at low and high pressure i.e. 1 psi (6.8.95 KN/m2) to 15000. psi (103.43 x 103 KNim2).

A protective cover (or cap/ 4 (Fig. 1) is provided for the valves when in normal (i.e. everyday) condition. Each of the valves 2 and 3 includes a valve member 5 of poppet type having a head 5A including a frusto conical tip making metal-to-metal sealing engagement with a corresponding seating 6A, 6B in the respective valve body portions 7, 8 of the valves. The body portions 7, 8 carry external threads 7A, 8A to enable the body portions to be screw threaded into threaded bores of the casing 1, for example a gate valve casing, for valve fitting, shoulders 7B, 8B on the body portions serving for the location of metal boss seals 11 to provide an external metal-to-metal seal.The poppet valve 5 moves on a bush insert 10 in the valve bore with a sealing ring 9 in a recess on a cylindrical wall of the head 5A sealingly engaging the insert 10.

Each poppet valve 5 is urged into a closure position by a compression spring 12 located betweem the valve 5 and a spring carrier 13, while each valve 5 includes internal ducting 14 for fluid flow through the valves, the ducting 14 including radial inlets 14A leading from a peripheral recess 5A on the valve while axial and radial discharge outlets 14B, 14C are provided at the poppet tip. The bush insert 10 includes transfer ports 10A, 10B at either end of a peripheral recess 10C of the insert, the function of which will be explained later. It is a feature of the valve assembly that downward opening movement of the poppet valve 5 of valve 2 causes opening movement of the valve 3 via the stem portion of valve 2. Operation of the valve assembly is effected by the installation of an operating or test tool 15 (Fig. 3).The tool 15 is of stinger type including a threaded nose 15A engaging in a threader cup portion 7C of body portion 7, a seal 16 e.g. a Dowty washer, being located between the tool 15 and the body 7, and opening of the check valves 2,3 is achieved by an actuating rod 17 of the tool 15.

Movement of the rod 17 is affected by a rotary thruster mechanism 18 including handle 18A, the mechanism 18 being threaded to a nut 19 to create the linear movement of rod 17, the nut 19 engaging a sealing gland 19A while grub screws 19B serve to locate the nut 19. The tool 15 houses ports 20 for the ducting 14 of the valves 2, 3; fittings or closures can be installed at the ports 20 as appropriate.

Fig. 4 shows the valves 2, 3 in the open position after actuation by the tool 15, in which position for example fluid/grease can be pumped through the ducting 14. Means are provided to limit the movement of the poppet valves 5, to avoid over compression of the springs 12, and in this example these means take the form of a stem seal comprising a head 21 on the rod 17 engaging with a corresponding seating 22 in the tool 15.

When the valve assembly 1 is installed and there is a requirement for, say "injection" the operating/test tool 15 is installed after sealing by rotating the handwheel 18A.

The nose (non-rotating) of the tool rod 17 engages the valve poppet 5 and moves the poppet 5 of the valve 2 outwardly to an open position while the outwards moving poppet of valve 2 engages and opens the poppet 5 of valve 3. A fluid flow path is consequently opened between the inlet 20 and the ducting 14 of both valves 2, 3. More specifically, referring to Fig. 4, in the valve open position outwards flowing fluid entering the valve 2 (and 3) is transferred via the ports 10A, the peripheral recess 10C and the ports 10B to the poppet recess 5B which in turn supplies to the ducting 14. This transfer arrangement obviates the possibility of back flow of fluid in the valve closure position, and also ensures that fluid passage or injection will occur only when the valves 2, 3 are in the correct open position. The springs 12 are prevented from exceeding their limits by the stem seal 21/22 on the tool 15 and this seal provides additional sealing at the seating 22.

The threading on nose 15A has the same diameter and is similar to the external threading 7A of valve body 7, so permitting, in a modification, with valve 2 omitted, the tool 15 to be threaded directly into the casing 1 to actuate the buried valve 3. With the tool 15 removed, the valve assembly 1 is capped by protective 'cover: 4 as shown in Fig.

1, to place the valve 1 in the normal (i.e. everyday) condition, the cap cover 4 giving an internal seal through a frusto-conical surface engagement between a nose 4A of the cover and the body portion 7. Further, an ItO" ring 23 is installed which prevents the ingress of undesirable substances e.g. dirt etc thereby protecting the threads to facilitate future installation of the tool 15.

Claims (19)

CLAIMS.

1. A check valve assemblage comprising first and second check valves each including an openable valve member, and means for the fitting of an operating tool for the valves, the arrangement being such that movement of the valve member of the first valve causes an opening movement of the valve member of the second valve.

2. An assemblage as claimed in claim 1, wherein the valves are in the form of poppet valves, spring means being provided to urge the valves to a closure position.

3. An assemblage as claimed in claim 1 of 2, wherein the valve assembly includes a valve body provided with external seal means, to enable the device to be sealingly fitted in a casing wall for example.

4. An assemblage as claimed in claim 3, wherein the valve body includes external thread means to enable the body to be screw threaded into threaded bore portions, a resilient seal being provided between the body and the casing wall.

5. An assemblage as claimed in any one of the preceding claims, wherein the operating tool includes a body provided with a screw thread enabling the tool body to be screw threaded to the valve body portion of the first check valve.

6. An assemblage as claimed in claim 5, wherein the tool includes an actuating rod located in a bore in the tool body operatively engagable with the valve member of the first valve.

7. An assemhlage as claimed in claim 5 or 6, wherein said screw thread of the tool body corresponds to said internal thread of the valve body whereby the tool may be screw threaded directly to said threaded bore portion.

8. An assemblage as claimed in any one of claims 5 to 7, wherein the tool body includes port means for fluid ducting of the check valves.

9. An assemblage as claimed in claim 5, wherein limiting means are provided to limit the possible opening movement of the check Valves.

10. An assemblage as claimed in claim 9, wherein the limiting means comprise a head on the actuator rod and a corresponding seating in the tool body.

11. A check valve assemblage including a check valve of poppet type, and an operating tool for said check valve of removable stinger form1 said tool including port means for the check valve.

12. An assemblage as claimed in claim 11, wherein a closure cap is provided for fitting to the check valve to place the valve in a sealed out-of-use condition when the tool is removed.

13. A valve assemblage substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

14. A poppet valve especially but not exclusively for use in a check valve assembly, said poppet valve comprising a valve body, a closure element moveable in the valve body and including a poppet head, the valve including a seat at a fluid inlet engagable by said poppet head at valve closure for closing said fluid inlet, ducting within said closure element including a fluid discharge, and fluid transfer means for transferring fluid from said fluid inlet to said ducting when the closure element is in an open position.

15. A poppet valve as claimed in claim 14, wherein the closure element moves on a bush or sleeve within said valve body, said bush providing duct meams constituting said fluid transfer means.

16. A poppet valve as claimed in claim 15, wherein the duct means includes a fluid inlet while the closure element includes an annular recess as part of said ducting, the fluid outlet feeding into said annular recess in a valve open position.

17. A poppet valve as claimed in any one of claims 14 to 16, wherein the closure element and the fluid inlet are arranged co-axially to permit an operating tool to pass through the inlet to engage the closure element.

18. A poppet valve as claimed in any one of claims 14 to 17, wherein the closure element is moved into said closure position by spring means.

19. A poppet valve substantially as hereinbefore described with reference to and as illustrated in Fig. 1 or Fig. 2 of the accompanying drawings.