GB2570703A

GB2570703A - Temporary valve cap

Info

Publication number: GB2570703A
Application number: GB1801813.5A
Authority: GB
Inventors: Velagala Sridhar; Vallis Richard; Skelding Dave; Andrew Currie Dean
Original assignee: BAE Systems PLC
Current assignee: BAE Systems PLC
Priority date: 2018-02-05
Filing date: 2018-02-05
Publication date: 2019-08-07
Anticipated expiration: 2038-02-05
Also published as: GB201801813D0; GB2570703B

Abstract

A temporary valve cap for a fluid filled pressure system having a multiplicity of valves comprises at least two elements 2, 3, wherein a first element 3 is reversibly affixed to a valve by a first thread 6, and a second element 2 is reversibly attached to the first element 3 via co-operating threads 4, 5, such that access to the valve requires removal of the second element 2 from the first element 3. The second element 2 is joined to the first element 3 by a tether 7. The temporary valve cap allows both easy attachment to a complex pressure system as well as testing of valves without damaging the system.

Description

The invention relates to a temporary valve cap, specifically to a cap that allows ready attachment to a complex system, and methods of testing whilst protecting valves on the complex system.

Many complex systems as they are built require maintenance and routine testing until they are fully commissioned.

According to a first aspect of the invention there is provided a temporary valve cap for a pressurised fluid system, said system comprising a multiplicity of valves, wherein said temporary valve cap comprises at least two elements, wherein a first element is reversibly affixed to a valve, and a second element is reversibly attached to the first element, such that access to the valve requires detachment of the second element from the first element.

The valve may typically comprise a valve seat and a mechanical valve assembly. The mechanical valve assembly may be selected from any type of valve, such as for example, a control valve, check valve, pressure release valves, flow valves etc. The valve may be a manually adjustable mechanical valve. The valve may be to check pressure or flow rates, or may be used to control or regulate flow of the fluid therein, or a combination of both.

During manufacture, installation or repair of complex high pressure systems, the system may need to be balanced, flows and/or pressures monitored at various joints or junctions to ensure correct operation of the complex system. It is imperative that whilst valves are not being interrogated that they are prevented from receiving accidental damage or that the valves flow setting is not accidentally changed. It has been found that repeated removal and refitting of prior art caps, which are one-piece, cause damage to the valve seat. Damage may occur be repeated removal, or dirt and grease ingress occurring between the valve seat and the valve caps.

In order to facilitate removal for examination of the mechanical valve assembly, the reversible attachment between the first element and the second element may be a screw thread, a hinge, biased push fit, magnetic fastener, or co-operative lug and void. In a highly preferred arrangement, the reversible

-2attachment is co-operative screw threads on the first element and second element.

The first element may have a first thread to provide a reversible fixture to the valve, and a second thread to provide a reversible attachment with a cooperative thread on the second element.

The reversible fixture of the first element to the valve may be infrequent, such as, only being fitted at the start of commissioning, build or maintenance and removal at the end of the commissioning, build or maintenance.

In order to facilitate removal, of only the second element and not both the first element and second element, the first thread and second thread on the first element may have opposite thread directions. Ina further arrangement the reversible fixture between the first element and valve may comprise a locking engagement to prevent unintended removal from the valve.

The reversible attachment of the second element to the first element is designed to be frequent, preferably more facile than for the reversible fixture between the first element and the valve.

In a highly preferred arrangement the second thread on the first element and co-operative thread on second element, is a quarter turn thread. This permits ready location of the first element and second element.

Typically, with one piece prior art caps, the cap is removed and located proximate to the valve. The prior art caps, once removed may be lost, if there is a delay between removal and testing of valves therein. Further prior art caps may be dropped or damaged after removal and therefore to avoid damaging the complex system, may be discarded rather than re-used. In a highly preferred arrangement there is a tether to retain the first element proximate to the second element, during removal. The tether may be a cord, strap, line, chain, articulated links, preferably the tether is flexible. The tether may be affixed to both the first and second element, by fixers. The tether may be any suitable material, such as a polymer, metal, metal alloy or composite material.

-3The valve typically comprises a body, a valve mechanism which allows fluid to flow, or allow pressures to be tested, and a valve seat upon which the permanent valve protection cover may locate on. In a highly preferred arrangement the first element provides protection of the valve seat, such as for example the first element may comprise a recess which accommodates the valve seat. The recess may allow the encapsulation of valve seat, on the surfaces that may be readily deformed by routine servicing and maintenance or installation processes. The top face of valve seat and side edges may be protected, as these are the surfaces that will provide a proper mating arrangement with the permanent valve protection cover. If the valve seat becomes damaged before final completion of the task, it may require parts of, or even the entire high pressure system to be de-commissioned, to replace the valve which includes the valve seat.

The first and second elements may be manufactured from any suitable material, and may be independently selected from metal, metal alloys, polymers, and a ceramic. The first and second elements are two housings which locate over and protect the valve. The first and second elements may be of any cross sectioned shape. The first and second elements may be tubular collars, which locate over the valve.

According to a further aspect of the invention there is provided a pressurised fluid system, comprising a multiplicity of valves, said valves comprising a seat, to provide engagement with a permanent valve cap, and a valve mechanism, wherein a temporary valve cap as defined herein is located thereon.

The pressurised fluid system may be a gas or liquid, which is contained under high pressure, such as for example, hydraulic fluids, oil, water, steam. The system may be used as a heating system or cooling system, or merely transferring fluids around a vehicle vessel or craft. The fluid may have a temperature above room temperature; the fluid may have a pressure above atmospheric pressure. Alternatively the pipe work may be evacuated, under vacuum, and have a pressure less than atmospheric pressure.

-4The temporary valve cover may provide protection to users nearby in the instance where there is an overpressure and the valve releases the fluid contained within the system, the temporary valve cover may prevent spraying of the fluid, and vent holes in the first or second element, allow excess fluid to escape in a particular direction away from the direction of users.

According to a further aspect of the invention there is provided a method of using a temporary valve cover as defined herein, on a system as defined herein, comprising the steps of,

a. reversibly attaching the temporary valve cover, which comprises the first element and second element, to a valve on the system,

b. detaching the second element from the first element to allow access to the valve,

c. performing the required process on the valve,

d. refitting the second element to the first element,

e. repeating the process steps of b to d, and on completion of the system, removing the temporary valve cap, and replacing with a permanent cap.

In a highly preferred arrangement there is a tether between the first element and second element, such that after step b, the first element may not be separated from the second element.

According to a further aspect of the invention there is provided a vehicle, vessel or craft comprising a pressurised fluid system as defined herein; comprising a temporary valve cap as defined herein, and optionally fitted by a method defined herein.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings of which:Figures 1a and 1b show a two part temporary cover, in a separated and joined arrangement.

Figure 2 shows the first element in contact with a valve assembly

-5Turning to figure 1a and 1b there is temporary valve cover 1, formed from a first element 3 and a second element 2. The first element (as shown in fig 2), is located on the valve. The first element is reversibly affixed to the valve by a first thread 6. The first element once in place does not need to be removed until the system has been commissioned, repair, maintained etc. The first element comprises a second thread 4, to reversibly attach with the co-operative thread 5, on the second element 2. The threads 4 and 6 may be threaded in opposite directions. Threads 4 and 5 are quarter-turn threads for facile alignment and quick fitting. The first element 3 and second element 2 are joined by a tether 7, in the form of a flexible metal braided wire, which is securely attached to the elements 2, 3 by fasteners 10a, 10b, via attachment hooks 12a, 12b respectively. The attachment hooks allow the wire 7 to move freely and prevent entanglement.

In order to aid fitting or removal of the temporary valve cover 1, or each of the first element 2 and/or second element 3, they may have voids 9a, 9b, for receiving a C-spanner. The second element may further comprise a knurled surface 8 to permit grip on the second element 3, to aid grip and subsequent removal.

In Fig 1b, on the lower surface 14 of the second element 3, there is provided a recess 13, which receives and preferably encapsulates the valve seat (see fig 2).

Turning to Figure 2 there is provided a valve 30 located on part of a complex pressurised system 37. The valve assembly 30 comprises a valve body 34, a valve mechanism 32, and a valve seat 33. The first element 23 has a first screw thread 26, which engages with a co-operative thread 31 on the valve body 34. The second thread 24 on the first element 23 may then receive and co-operatively engage the second element (removed for clarity). The first element 23, with the second element removed allows ready access to the valve mechanism 32, such that an external valve tool 35 may be engaged with the valve mechanism 32. The valve tool may be a pressure gauge, a tap/lever to alter flow rates, or an electronic activator/actuator to activate a motorised valve mechanism. Once the process on the valve mechanism 32 has been completed

-6the tool 35 is disengaged and the second element may then be replaced, as shown in fig 1b.

The valve seat 33 may allow proper engagement with the final permanent valve cover once the system has been maintained, serviced, 5 commissioned. The first element 23 has a recess which accommodates, preferably encapsulates entirely the valve seat, to protect the upper face of the seat 36 and edges 38. If the valve seat is damaged it may need to be replaced which may involve the part of or even entire complex system 37, to be decommissioned. The valve seat 33 may be required to form a fluid tight seal 10 with a further component in the final commissioned system, and hence preserving the integrity of the valve seat will reduce downtime and associated costs.

-7Claims

Claims

1. A temporary valve cap for a pressurised fluid system, said system comprising a multiplicity of valves, wherein said temporary valve cap comprises at least two elements, wherein a first element is reversibly affixed to a valve, and a second element is reversibly attached to the first element, such that access to the valve requires detachment of the second element from the first element.

2. A valve cap according to claim 1, wherein the valve comprise a valve seat and a mechanical valve assembly.

3. A valve cap according to claim 2, wherein the mechanical valve assembly is a control valve, check valve, pressure release valve.

4. A valve cap according to any one of the preceding claims, wherein the reversible attachment between the first element and the second element is a screw thread, a hinge, push fit, magnetic faster, co-operative lug and void.

5. A valve cap according to claim 4, wherein the first element has a first thread to provide a reversible fixture to the valve, and a second thread to provide a reversible attachment with a cooperative thread on the second element.

6. A valve cap according to claim 5, wherein the first thread and second thread on the first element have opposite thread directions.

7. A valve cap according to any one of claims 5 to 6 wherein the second thread on the first element and co-operative thread on second element, is a quarter turn thread.

8. A valve cap according to any one of the preceding claims wherein there is a tether to retain the first element proximate to the second element, during removal.

9. A valve cap according to claim 8, wherein the tether is a cord, strap, line, chain, articulated links affixed to both the first and second element.

10. A valve cap according to any one of the preceding claims wherein the first element comprises a recess which accommodates the valve seat.

11. A valve cap, wherein the first and second elements are independently selected from a metal, metal alloys, polymers, and a ceramic.

12. A pressurised fluid system, comprising a multiplicity of valves, said valves comprising a seat and a valve mechanism, wherein a temporary valve cap according to any one of the preceding claims is located thereon.

13. A method of using a temporary valve cover according to any one of claims 1 to 11, on a system according to claim 12, comprising the steps of,

a. reversibly attaching the temporary valve cover to a valve on the system,

b. removing the second element from the first element to allow access to the valve,

c. performing the required process on the valve,

d. refitting the temporary valve cover,

e. repeating the process steps of b to d, and on completion of the system removing the temporary valve cap, and replacing with a permanent cap.

14. A method according to claim 13, wherein there is a tether between the first element and second element, such that after step b, the first element may not be separated from the second element.

15. A vehicle, vessel or craft comprising a pressurised fluid system according to claim 12.

Intellectual Property Office

Application No: GB1801813.5 Examiner: Vaughan Phillips

Claims searched: 1-15 Date of search: 25 July 2018

Patents Act 1977: Search Report under Section 17

Documents considered to be relevant:

Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-6, 10-12 EP 2905407 Al (DORMA) see abstract X 1-4, 10-12 US 2015/0345658 Al (JB INDUSTRIES) see abstract X 1-4, 10-12 US 2012/0211682 Al (SHAIO) see abstract X 1-4, 10-12 US 2006/0070662 Al (GREMILLION) see abstract X 1-4, 10-12 US 6176255 Bl (ROBINSON) see abstract X 1-5, 10-12 US 4182361 A (HYDRA-GUARD) see abstract