AU715355B2 - Isolating valve - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicants: To. Flo 6n oL ri LTt A.C.N. 000 922 6 A.C.N. 000 922 690 Invention Title: ISOLATING VALVE The following statement is a full description of this invention, including the best method of performing it known to us: 2 15 ISOLATING VALVE This invention relates to an Isolating Valve, and more particularly a high pressure ball valve for incorporation into a pipeline, pump, valve stem of another valve or other associated equipment such as may be used in installations for oil and gas, and for the purpose of injecting sealant and/or lubricant.

With such valves it is the practice for the valve *to carry an injection nipple with a spring operated ball check valve interposed between the main ball valve and the injection nipple. There is a cap which is fitted over the injection nipple which provides a secondary seal and also performs the additional function of preventing the ingress of dirt. When it is required to inject sealant the cap is removed which just leaves the ball check valve as the only seal between the pipeline and atmosphere. The injection gun is fitted over the injection nipple and sealant is forced in pushing the ball check valve off its seat. Once the gun is removed the ball check valve returns to its seat preventing leakage of fluid from the line. The major risk with this setup is with the main cap removed for fitting the injection gun, the only seal between the pipeline and 11.\Kep~pnpo156loc 10/06,'97 3 the atmosphere is the ball check valve. The method of overcoming this is to interpose a manually operated ball valve between the injection nipple and the pipeline ball valve.

One problem with such valves is the requirement to have two separate items associated with the valve, namely the injection nipple and the manually operated ball check valve, which results in a total valve length which takes up space, whilst also subject to being accidentally knocked and as a result broken or damaged.

The object of the present invention is to provide a ball valve with a ball check valve and an injection 15 nipple that is more compact whereby to avoid the problems referred to above.

The invention therefore envisages an isolating valve comprising a main ball valve and an injection nipple associated therewith and through which substances such as sealants and lubricants can, in use, be injected into equipment associated with the isolating valve, wherein a spring biased ball check valve is incorporated between said injection nipple and said main ball valve.

With such an arrangement, the requirement for a separate manually operated ball valve, adding to the length of the valve, is dispensed with, and the length of the ball valve/injection nipple combination is significantly reduced.

Preferably the inlet end of the injection nipple is closed by a cap providing an additional seal against any leakage past the spring biased ball check valve.

One preferred embodiment of the invention will now be described with reference to the accompanying H:\Loanne\Kecp\po1566.dOC 10/06/97 4 drawings, in which; Figure 1 is an end elevational view of the embodiment of the isolating valve, and Figure 2 is a longitudinal cross-sectional view taken along line 2-2 of Figure 1.

In this preferred embodiment of the invention the valve, generally indicated as 10, comprises an elongate main valve housing 11 incorporating an axial supply port 12 at one end for fluid communication with associated ^equipment, such as pipeline valve (not shown), via an external screw threaded portion lla on the end of the 15 housing 11. The port 12 opens into a valve chamber 13 within which a main ball valve 14 is situated having a passage way 14b therethrough. Seals 14a are provided between the valve ball 14 and the walls of the valve chamber 13, whilst the valve ball 14 is carried by a valve stem 15 with a radially extending flange 16 received within a circular cavity 17 in the housing 11 adjacent to the valve chamber. The flange 16 bears against one of the seals 14a, whilst an additional sealing washer 14c is provided between the flange 16 and the cavity 17.

An operating handle 18 is attached to the external end of the valve stem 15 by a bolt 19, with a pair of friction washers 20 interposed between the handle 18 and an external surface 21 of the main valve housing 11. A stop pin 22 is carried by one end of the handle 11 and is received within a slot 22 the ends of which slot define the limits of movement of the handle and rotation of the valve stem 15 and associated valve ball 14 between fully open and fully closed positions of the valve.

On the side of the valve chamber 13 opposite to the axial supply port 12 is a ball check valve and H:\Leanne\Keep\po1566.doc 10/06/97 5 injection nipple chamber 23 extending axially of the main valve housing and opening through the end thereof, and which chamber receives a spring biased check valve 24 and an injection nipple 25 which together constitute an assembly 26. The assembly 26 comprises an end portion 29 of the injection nipple 25 of the assembly 26, with an axially extending transfer port 27 therethrough communicating with the valve chamber 13 and with a ball check valve chamber 28 within the assembly 26 and via a plug member 30 with an aperture therethrough which receives one end of a compression coil spring 31. The other end of the spring 31 is received within a ball chamber 32, communicating with an inlet port 33, whilst the spring 31 urges a valve check ball member 34 against a ball valve 15 seat 35 surrounding the inner end of the inlet port 33.

The outer or inlet end of the inlet port 33 is flared S"outwardly to provide a conical seat 36 for an inwardly tapering sealing portion 37 of a removable closure cap 38 •screw threaded at 39 onto the end of the main valve housing 11. The sealing cap 38 therefore provides the dual purpose of a seal and a barrier against ingress of foreign material into the injection nipple.

o **.The valve 10 therefore incorporates three 25 separate elements to prevent fluid leakage through the ooeoo valve, namely, the main ball valve 14, the check valve 24 and the sealing cap 38.

In a situation where the associated pipeline valve is required to have materials, such as a sealants or lubricants, injected into it, the sealing cap 38 with the main ball valve 14 opened, is partially unscrewed from the main housing 11, allowing inspection, via observation ports of the outer end of the inlet port 33 for the injection nipple 25, to determine whether there is any fluid leakage past the ball check valve 24. In the case of observation of leakage, the sealing cap 38 can be screwed fully back i\Learne\Kee\po1 5.do c 10/06/97 6 into position and the main ball valve 14 closed. The sealing cap 38 can then be unscrewed to observe whether a complete seal has been effected between the nipple and the associated pipeline valve. In the situation where no fluid leakage passes the ball check valve 24, the sealing cap can be totally unscrewed from the main housing 11 and the sealant gun fitted. As the sealant is injected into the nipple the main ball valve 14 can be opened allowing sealant to be injected into the pipeline valve. Once sufficient sealant has been injected the main ball valve 14 can be closed prior to removing the sealant gun in case the ball member 34 of the check valve 24 does not re-seat S• immediately on the ball valve seat 35. Thereafter the injection gun is extracted from the injection nipple 25 and the sealing cap screwed back onto the valve housing 11 with surface to surface contact provided between the conical seat 36 at the inlet to the inlet port 33 and the tapering sealing portion 37 of the sealing cap, whereby to provide an additional seal whilst also preventing the ingress of foreign material into the injection nipple.

The major components of the valve, in the case of installations containing fluids under high pressure, are formed from metals such as stainless steel, whilst the various sealing washers and rings are formed from rubber or plastics materials which are conventional for such seals.

H:\Leanne\Keep\po1566.doc 10/06/97

Claims (7)

1. An isolating valve comprising a main valve and an injection nipple associated therewith and through which substances such as sealants and lubricants can, in use, be injected into equipment associated with the isolating valve, wherein a spring biased ball check valve is incorporated between said injection nipple and said main valve.

2. An isolating valve as claimed in Claim 1, wherein a cap is provided to close an inlet end to said injection nipple to provide a seal in addition to said main valve and said ball check valve.

3. An isolating valve as claimed in Claim 2, wherein at least one inspection port is provided through said cap to allow visual inspection of the interior of the injection nipple to determine, upon partial removal of the cap and opening of the main valve, whether there is any leakage of material from the associated equipment past the ball check valve and before the cap is completely removed.

4. An isolating valve as claimed in Claim 2 or 3, **wherein a conical valve seat is provided at the entrance to 25 the inlet end of said injection nipple, and said cap has a mating conical sealing portion to seat on said conical valve seat when said cap is in position to thereby close said inlet end of said injection nipple.

5. An isolating valve as claimed in any one of the preceding claims, wherein said main valve and said ball check valve are contained within a single housing.

6. An isolating valve as claimed in any one of the preceding claims, wherein said main valve is a main ball valve, and an externally manually operated handle controls the opening and closing of said main ball valve via a valve H: \Leanne\Keep\poI566doc 10/06/97 -8 stem, and wherein means are provided to limit the movement of the handle and therefore the main ball valve between fully open and fully closed positions of the valve.

7. An isolating valve substantially as hereiabefore described with reference to the accompanying drawings. Dated this 10th day of June 1997 KRYSTONR IMACIFIC PTV L;1I;qHD -'CO rto' co~o Pr& P' -i By their Patent Attorneys V 3T) GRIFFITH HACK 7Z S Fellows Institute of Patent 7O Attorneys of Australia Fr 000. 0.**0 .0.0* .doc 10/06/91