AU725737B2

AU725737B2 - A tool for servicing stopcock valves

Info

Publication number: AU725737B2
Application number: AU52172/98A
Authority: AU
Inventors: Scott Michael Hogan
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-01-28
Filing date: 1998-01-20
Publication date: 2000-10-19
Anticipated expiration: 2018-01-20
Also published as: AU5217298A

Description

4,ASTRALIA C& PATENTS ACT 1990

COMPLETESPCFATO

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: f.

I

Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: Scott Michael Hogan Address of Applicant: Actual Inventor: Address for Service: 1 Superba Avenue, CRONULLA NSW 2230 AS ABOVE/V ef 10 Hafrrianr Avnu DNfi- BAY N.S.W 2226 for the invention entitled: A TOOL FOR SERVICING STOPCOCK VALVES Complete Specification The following statement is a full description of this invention, including the best method of performing it known to me: This invention relates to plumbing apparatus and more particularly although not exclusively it discloses a tool for replacing or repairing stopcock valves in fluid pressure systems such as water supply pipes.

With some stopcocks such as those for example at the water supply meters of domestic or commercial premises it is not possible to shut off the water pressure for maintenance of the valve without either freezing the pipe upstream of the stopcock or excavating to, find and close a valve in the main supply line. In the former case the freezing operation, which requires special equipment and the use of supercooled liquified gas is relatively expensive. The latter procedure is laborous, time consuming and sometimes not successful as the mains valve cannot always be located. While it is also known in areas where the pressure is relatively low to replace stopcock valves without shutting down the supply this can be difficult and usually involves substantial wastage of water.

It is therefore an object of this invention to ameliorate the aforementioned disadvantage and accordingly there is disclosed an apparatus for servicing a stopcock valve assembly in a pressurised system comprising first and second chambers connectable through an isolation valve means, said first chamber being releasably securable over said stopcock valve assembly in a substantially pressure-tight fit by a clamp means, said second chamber including a rotatable shaft -2protruding through a wall of said second chamber and being movable lengthwise through said chambers to engage and remove said stopcock valve assembly and means for equalising and releasing fluid pressure in said second chamber.

In another aspect this invention discloses a method of servicing a stopcock valve assembly in a pressurised fluid system using the above apparatus, said method including the steps of: securing said first chamber over said stopcock valve assembly and equalising the pressure in said connected first and second chambers with said fluid system, using said shaft to withdraw the stopcock valve i: assembly into said second chamber, isolating and depressurising said second chamber, removing said stopcock valve assembly from said second chamber for service or replacement, inserting the repaired/replacement valve assembly back into said second chamber, repressurising said second chamber, and fitting the serviced/replacement valve back into said stopcock housing.

The currently preferred form of this invention will now be described with reference to the attached representations in which: Figure 1 shows a clamp assembly for securing the first and second chambers over a stopcock valve, Figure 2 shows the clamp of figure 1 installed on a typical stopcock housing and valve assembly, Figure 3 is a schematic elevational view of the chambers fitted over this stopcock valve assembly, and Figure 4 is a schematic elevational view of a second embodiment of the invention.

Referring first to figure 1 there is a clamp assembly comprising two half sections 1, 2 which when fitted together using bolts 3 form a rigid block with a central bore 4 and lower circular flange 5. This flange 5 is relatively thin (say about 1 mm) and defines an aperture 6 of reduced diameter. There is also a square plate 7 below with a series a.

of four bolts 8 (only three being shown) extending up into the undersides of the half sections 1 and 2. As best shown in figures 2 and 3 this clamp assembly is fitted onto the stopcock housing 9 by first unscrewing the stopcock valve assembly 10 from the housing sufficiently to receive the edge of the flange 5. This enables the sections 1 and 2 to be fitted in from each side and then bolted together. The diameter of the aperture 6 is sufficient to clear the threads of the valve assembly 10 while still engaging between the bonnet 11 of the valve assembly and the adjacent rim 12 of the housing.

It has been found through trials by the inventor that this procedure can be readily conducted at full mains pressure with only a minor leakage of water through the loosened stopcock valve threads. The plate 7 is then fitted under the stopcock housing and the bolts 8 tightened to securely clamp the block in place. The two sections 1 and 2 preferably have mating contact surfaces to minimise leakage therebetween. The upper faces 13 of these sections are also machined to sit flush and have four threaded bolt holes 14 placed symmetrically around the bore 4 to form a stable rigid base on which to bolt the chambers. As shown in figure 3 these chambers 15 and 16 are disposed end to end and are connected through a gate valve 17. They are each large enough to o contain the valve assembly 10. The lowermost chamber 15 as shown is formed with a bottom flange 18. After removal of the key 19 from the valve spindle 20 this chamber 15 is placed *0 over the valve assembly 10 and is secured to the faces 13 by means of four bolts 21 extending through the flange 18 and into the holes 14. There may also be valves 22 and 23 to release fluid pressure from each chamber to atmosphere and a valve 24 to equalise pressure between the chambers. The uppermost chamber 16 is fitted with a shaft 25 which protrudes in through a gland 26 in a removable end cap 27.

This shaft is slidable in the gland and is long enough to extend down to the stopcock valve assembly 10 in the lower chamber 15. The inner end of this shaft is also fitted with a suitable socket 28 to grasp and turn the cap nut 29 of the stopcock valve assembly.

With the apparatus fitted as described above. the shaft 25 may thus be slid down and the socket used to engage and turn the loosened valve assembly 10 completely out of the housing 9.

Following this the valve can be withdrawn on the shaft i nto.

the upper chamber 16, the gate valve 17 closed, the pressure in chamber 16 dissipated to atmosphere and the valve assembly removed through end cap 27 for servicing or replacement. The replaced or repaired valve assembly is then placed back into the chamber 17, the chamber sealed and pressurised, the gate valve 17 opened and the valve assembly screwed back into the housing to loosely contact the flange 5. After removal of the chambers and clamp the stopcock valve assembly can then be tightened completely to render the system again operational.

second embodiment of the invention is shown in figure 4.

This device in principle operates in the same manner as the ***apparatus of figure 3. Thus the same reference numerals with the addition of the letter have been used for corresponding features. In this case the two chambers 15a and 16a are connected by a rotatable ball valve 30 which is operable by a crank handle 31. There is a shaft 25a which is :slidably fits through a gland 26a in a removable end cap 27a of the upper chamber 16a. The inner end of this shaft is fitted with an expandible collet 28a such as that produced by to grasp the end of the stopcock valve spindle 32. With this particular embodiment the collet is adapted to accomodate spindles from 9 to 15 mm, although the invention is not limited to this particular size range. The two half sections la and 2a in this case are secured together by bolts 3a (shown in end section only) which extend in from one side through both half sections and also enage in horizontal grooves 33 in the base 34 of the lower chamber 15a. In this way the two halves la and 2a when secured together form a rigid block or collar around the loosened stopcock valve and also lock onto the upper and lower chambers 15a and 16a in a single operation. As with the previous embodiment these half sections together define a central bore and lower circular flange 5a which forms an aperture of reduced diameter. The diameter of the aperture is sufficient to clear the threads of the loosened valve assembly 10a while, still engaging between the bonnet lla and adjacent rim 12a of the housing. This second embodiment also employs a set of hooks and 36 which extend under the stopcock housing 9a to securely clamp the half sections la and 2a in place. These hooks are tightened by means of nuts 37 and 38 which can be turned down on the threaded shanks 39 and 40 of the hooks.

p For the purposes of this specification expressions such as "upper", "lower" and "horizontal" etc. refer to the apparatus in a position of use as illustrated and are not to be read as necessarily limiting.

It will thus be appreciated that this invention at least in the form of the embodiments disclosed provides a novel and useful tool for servicing stopcock valves without any disruption to the water supply. Clearly however the examples described are' lonly the currently preferred forms of this invention and a wide variety of modifications may be made which would be apparent to a person skilled in the art. For example construction of the clamp for securing the chambers onto the stopcock housing and the shape and configuration of the chambers themselves may all be changed according to design preference or the size or type of stopcock valve to be serviced.

C C -8-

Claims

1. An apparatus for servicing a stopcock valve assembly in a pressurised fluid system, said apparatus comprising first and second chambers connectable through an isolation valve means, said first chamber being releasably securable over said stopcock valve assembly in a substantially pressure-tight fit by a clamp means, said second chamber including a rotatable shaft extending through a wall of said second chamber and being movable lengthwise through said chamber to engage and remove said stopcock valve assembly and means for releasing fluid pressure in said second chamber wherein said clamp means includes component sections which when fitted together form a block or collar with a bore and lower flange defining an aperture of reduced dimensions relative to said bore, said component sections being adapted to be secured together around said stopcock valve when said valve is loosened so that said flange engages between the bonnet of said valve assembly and the rim of the valve housing. a

2. The apparatus as claimed in claim 1 wherein said clamp means further includes a set of hooks which in use of said apparatus extend down from said fitted component sections and under the housing of the stopcock valve to hold said block or collar in place on said housing when said stopcock valve assembly is removed from the housing. -9- 9 /7 )ooO

3. The apparatus as claimed in claim 2 wherein the component sections are secured together to form said block or collar by bolts which extend in from the side through said component sections and engage in one or more recesses in the base of said first chamber to thereby secure said first chamber to said block or collar.

4. The apparatus as claimed in claim 3 wherein said isolation valve means is a ball valve located between adjacent ends of said first and second chambers.

The apparatus as claimed in claim 4 wherein an inner end of said rotatable shaft is fitted with an expandable collet to grasp the end of the stopcock valve spindle.

6. The apparatus as claimed in claim 5 wherein said first and second chambers are elongated and said rotatable shaft extends through an end wall of said second chamber opposite said isolation valve means.

7. A method of using the apparatus of claim 1 to service a stopcock valve assembly in a pressurised fluid system, said method including the steps of: Securing the first chamber over said stopcock valve assembly and equalising the pressure in said connected first and second chambers with said fluid system, using said shaft to withdraw the stopcock valve ~zip S~dlpC~ I? /Jjpooo assembly into said second chamber. isolating said second chamber from said first chamber. depressurising said second chamber. removing said stopcock valve assembly from said second chamber for repair or replacement. inserting the repaired/replacement valve assembly back into said second chamber. repressurising said second chamber, and fitting the repaired/replacement valve assembly back into the stopcock housing.

8. The method as claimed in claim 7 wherein the step of securing the first chamber over said stopcock valve assembly includes loosening the stopcock valve from the valve housing.

9. Apparatus for servicing a stopcock valve assembly in a pressurised fluid system, said apparatus being substantially as described herein with reference to figure 1 to 3 or figure 4. -11- -ll-