GB2096929A - Valve removal tool - Google Patents

Abstract

The actuator of a valve removal tool (10) is provided as two interrelated members: a tubular piston (104) having a working head (114) provided at one end, and a non- rising, rotatable stem (76). The housing (12) of the tool provides a cylinder (108) for the piston and journals the stem. The piston is keyed to the stem (at 86) for rotation therewith. The piston is fluid pressure operated and double-acting, there being two respective pressurization ports (88, 90) through the housing. Accordingly, the working head can be advanced and retracted without being rotated, through the application of fluid pressure to axially opposite sides of the piston, and the working head can be rotated without being advanced or retracted, by rotating the stem through a crank (78). The housing is shown provided with a view port (136) for inspecting the spatial position of the piston, and thus ascertaining the longitudinal and angular position of the working head. <IMAGE>

Description

SPECIFICATION Valve removal tool The present invention relates to. apparatus useful in a procedure for installing and removing a valve while maintaining control of pressure in the piping system or the like immediately upstream of the location of the valve. Common names for the apparatus of the particular type are "plugging tool" and valve removal tool. Typically when a valve is to be removed from a line the valve is closed and the flange at its downstream end is disconnected from the system. The tool is readied with a plug and sealingly secured to the flange.

The valve is then opened and the tool is operated to insert the plug, through the downstream section of the housing throughbore and the valve cavity and into and through the upstream section of the housing throughbore where it is sealingly fastened in place in the bore of the pipe joint or the like immediately upstream of the valve. For this purpose, the pipe joint e.g. may originally have been provided with internal threading to mate with external threading on the pipe plug. The task of inserting the plug accomplished, the head of the tool is retracted from the plug, and the valve may safely be disinstalled. Upon installation of a repaired, reconditioned, different or new valve on the plugged line, the tool or a similar one may be similarly used to remove and withdraw the plug, whereupon the valve may be closed, and the downstream piping reconnected to the valve.

According to the invention the actuator of a valve removal tool is provided as two interrelated members: a tubular piston having a working head provided at one end, and a non-rising, rotatable stem. The housing of the tool provides a cylinder for the piston and journals the stem. The piston is keyed to the stem for rotation therewith. The piston is fluid pressure operated and doubleacting, there being two respective pressurization ports through the housing. Accordingly, the working head can be advanced and retracted without being rotated, through the application of fluid pressure to axially opposite sides of the piston, and the working head can be rotated without being advanced or retracted, by rotating the stem. A crank is shown for rotating the stem.

The housing is shown provided with a view port for inspecting the spatial position of the piston, and thus ascertaining the longitudinal and angular position of the working head.

The principles of the invention will be further discussed with reference to the drawings wherein a preferred embodiment is shown. The specifics illustrated in the drawings are intended to exemplify, rather than limit, aspects of the invention as defined in the claims. In the Drawings: Figure 1 A is a longitudinal sectional view of one (outer) end portion of the valve removal tool; and Figure 1 B is a longitudinal sectional view of the other (inner) end portion of the valve removal tool.

Figures 1 A and 1 B can be assembled to one another along the dash-dot lines A-A, B-B to provide an indication of the appearance and structure of the whole tool. In practice the tool may be made relatively longer, or shorter, in order to provide for more, or less, maximum/longitudinal extension of the working head.

The valve removal tool 10 includes a housing 12 that is shown comprising a tubular body 14 having an inner end cap 1 6 and an outer end cap 1 8. Each end cap includes a respective end wall 20, 22 with a respective central opening 24, 26 and a respective tubular skirt 28, 30. The caps 1 6, 1 8 are shown screwed onto the respective end of the tubular body 14 at 32, 34, with cap-to-body annular seals shown being provided at 36, 38. The caps are retained in place by respective set screw means 40, 42.

Each end cap is shown coaxially provided with a tubular boss 44, 46 extending from its end wall in the axially opposite direction from the respective cap skirt. The l.D. of each boss 44, 46 is somewhat larger than the diameter of the respective cap end wall central opening 24, 26 to provide a respective annular support shoulder for the one end of a respective stack 48, 50 of annular bearing and seal elements.

At the inner end, the stack 48 is shown held in place by a split ring retainer 62 that fits in a corresponding, circumferentially extending, radially inwardly opening internal groove in the boss 44. At the outer end, the stack 50 is shown held in place by a packing retainer 54 which seats on the axially outer end of the boss 46 and thereby projects into the boss to a limited extent.

The packing retainer 54, in turn, is held in place by a further cap-like bearing housing 56, which has an end wall 58 and a tubular skirt 60. The skirt 60 is internally threaded to screw onto the boss 46 until its internal shoulder 62 engages the packing retainer 54. A set screw 64 locks the bearing housing 56 in place. The bearing housing end wall 58 is provided with a central opening 66.

Within the end wall there is provided a radially inwardly opening circumferential groove for receipt of an annular radial bearing 68 and an annular stem wiper 70. The opening 66 is of lesser diameter than the l.D. of the skirt 60 to provide a bearing chamber in which two stacks 72, 74 of annular thrust bearing members are received with axial spacing between them.

The bearings 68 and 72, 74 respectively radially and axially support a non-rising, rotatable stem 76 which projects out of the bearing housing 56 through the central opening 66. Outside the housing, the stem 76 is shown provided with means for rotating it. Typically, this is a hand crank 78 secured to the outer end of the stem at 80.

(The rotating means could be a hand wheel, a gear motor or the like.) The stem 76 extends axially inwardly through the boss 46 in which it is radially journalled and sealed with respect to the end cap 1 8 by stack 50 of annular bearing and seal elements. The stem 76 further extends axially inwardly through the central opening 26 of the end cap 1 8 into the cylinder chamber 82 provided within the housing body 14 between the end caps 16, 18. The axially inner end of the stem 76 is shown located at 84 near the axially inner end of the chamber 82.

Throughout substantially the full length of the chamber 82, the stem 76 is shown provided with an essentially longitudinally extending, radially outwardly opening keyway 86.

The housing is shown provided with two pressurization ports for the chamber 82, one (88) at the axially inner end of the chamber 82 and the other (90) at the axially outer end of the chamber 82.

To provide the port 88, the side of the cap 1 6 end wall 20 facing the chamber 82 is grooved perimetrically of the central opening 24 to provide a recess that receives an annular seal ring 92 that is backed by an annular member 94 which functions as a retainer for the seal ring 92 and as a slide bearing for the piston (to be described). An annular, radial flange portion 96 of this annular member 94 seats on the end wall 20 perimetrically of the groove in which the seal ring 92 is received. This flange 96 extends radially outwards to the internal wall of the boss 44, so that as the cap 1 6 is screwed onto the body 14 it becomes sandwiched between the axially inner end of the body 14 and the cap 16 end wall 20.As seen at the left in Figure 1 B, the axially outer face of the flange 96 is provided with a radially extending groove 98 to provide a channel around the axially inner end of the body 14. This channel communicates the chamber 82 with the internal wall of the boss 44. At the site where the channel 98 opens against the boss 44 an opening 100 is provided radially through the boss. This opening 100 is shown being internally threaded so that a conduit communicating with a source of fluid pressure (e.g. air or hydraulic fluid) can be connected therewith in use. The opening 100 and channel 98 together constitute the port 88.

To provide the port 90 an internally threaded opening is provided radially through the end wall 22 of the cap 18 at a level which communicates past the axially outer end of the body 14 with the chamber 82. The internal threading is for connection of a respective fluid pressure supply conduit thereto in use.

Within the chamber 82 there is axially slidingly received a tubular piston member 102. This member has a tubular piston portion 104 that is shown externally provided with two axially spaced circumferential seals 106 in sliding contact with the internal wall 108 of the body 14. Between these seals 106, the piston 104 is shown provided with a radial bearing means, e.g. a piston ring 1 09.

Internally the piston 104 is shown provided with a keystock that is captivated in the stem keyway 86.

In Figures 1 A and 1 B, the piston member 102 is shown fully retracted, i.e. with the piston 104 located at the axially outer end of the chamber 82.

The piston member further includes a tubular tail 110 that integrally coaxially extends inwardly from the piston portion 104. This tail is so long that even when the piston is fully retracted as shown the tail extends out of the chamber through and in sliding, sealing contact with the seal ring 92, through the central opening 24 of the cap 16, through and in sliding, sealing and bearing contact with the stack 48 of annular bearing and sealing elements and axially inwardly past the axially inner end 112 of the inner end cap tubular boss 44.

Accordingly, when the boss 44 end 112 is clamped or otherwise secured to the corresponding flange of the housing of the valve that is to be installed or removed, the portion of the piston tail shown exposed in Figure 1 B will project into the valve housing.

This exposed portion of the piston tail comprises the working head 114 of the tool. The details of the working head shown are illustrative.

Here, the working head is shown including a ball check valve 116 screwed into an internally threaded circumferential boss in the longitudinal bore 118 of the tail 110. The check valve 116 includes a body 1 20 sealed to the bore by an annular sealing ring 122. The passage 124 of the body 120 includes a valve seat against which a ball 126 is pressed by a spring 128 that is mounted to the body 120 by a tubular ball check retainer 129 which provides a continuation of the passage 124. The body 120 further includes a coaxially inwardly extending stinger 1 30 with a shaped end surface 132 for grasping the valve that is to be installed or removed. All of this is recessed within the bore of the piston tail 11 0, although near its free radially inner end.At the level of the stinger end surface 132 the piston tail is internally circumferentially grooved to receive an O-ring seal 132, also for circumferentially engaging the valve that is to be installed or removed.

A typical tool 10 of the present invention is sized to provide a twelve inches of piston travel between the fully retracted condition shown in Figures 1 A and 1 B and the easily conceived of fully thrust position where the piston 104 would be located near the axially inner end of the chamber 82, e.g. by the end cap 16, and the tail with its working head would be correspondingly further projected past the end 112 of the cap 1 6.

Other lengths of maximum extension are possible, e.g. by substituting for the body 14, piston member 102 and stem 75 shown a set that is correspondingly longer. The telescopic relationship of the piston member and stem, with each principaily slidingly journalled in or on an opposite end cap of the housing provides a smoothly operating device, even where the amount of thrust needed is fairly long. This allows access to plug sites that are fairly inaccessibly located deeply through the valve bore housing and pipe bore or the like.

In use, the working head is extended and retracted by pressurizing the respective port of the housing while allowing the other to exhaust or drain, and the working head is rotated (independently of the extension/retraction) by rotating the stem 76 (to which the piston is keyed). The stem 76 is rotated using the external actuator, e.g. crank 78, provided at the opposite end of the tool from the working head.

For use in those times when, for one reason or another the spatial disposition of the working head becomes a matter of curiosity while the tool 10 is in use, the cap 1 6 preferably is provided with a view port 136, e.g. extending radially through the end wall 20 to intersect the piston tail between the seal rings as shown. To aid in this analysis, the piston tail may be externally provided with indicia (not shown) indicating various longitudinal and angular positions. The radially outer end of the view port 136 is shown being threaded and normally receiving a closure plug 138 for protection of the piston tail until observation is necessary or desired.

No parts of the device 10 need be made of unusual materials.

Claims (5)

1. A valve removal tool, comprising: a housing including a tubular body having opposite end cap means providing a chamber within the body; a tubular piston slidingly received within the chamber and having a tail portion slidingly, sealingly extending out of the housing through one of said end cap means; a working head provided on said tail portion effectively outside of the housing for operatively gripping a valve to be installed in or removed from a valve housing; a non-rising stem journalled in the housing for rotation, this stem being telescopingly received in the tubular piston and sealingly extending out of the housing through the other of said end cap means; means effectively keying the stem to the housing of said tool for rotating said stem;; means effectively keying the step to the working head of the piston so that as the stem is rotated the working head is correspondingly rotated; first and second fluid pressurization ports provided through the housing to communicate with the chamber on effectively opposite sides of the piston so that as the chamber is pressurized via one port and the other port is vented, the piston and said working head are moved longitudinally in one axial direction and as the chamber is pressurized via the other port and the one port is vented, the piston and said working head are moved longitudinally in the opposite axial direction, whereby the working head may be extended and retracted without being rotated and rotated without being extended and retracted.

2. The valve removal tool of claim 1, wherein: said means for rotating the stem comprises a hand crank secured on the stem.

3. The valve removal tool of claim 1, wherein: the stem is effectively keyed to the working head by being keyed to the piston.

4. The valve removal tool of claim 1, further including: an observation port provided through the housing at a site where the piston may be observed while the tool is in use, as an indication of the spatial disposition of the working head.

5. A valve removal tool substantially as hereinbefore described with reference to the accompanying drawings.