Securing a plug assembly in a valve
A plug assembly is configured for use in a valve. These configurations may include a plug with a sealing surface that can interface with a seat to regulate flow of fluid through the valve. A keyed shaft may insert into the plug. The keyed shaft can rotate to change location of key members in the plug. In one implementation, a technician can rotate the keyed shaft from a first position to a second position at which the key members couple the plug with the valve body.
1 . A valve, comprising:
a valve body having a flow path;
a boss disposed in the flow path; and
a plug assembly coupled to the boss, the plug assembly comprising,
a plug having a first bushing with a top and a bottom and a bore extending therethrough, the plug comprising a first longitudinal slot extending from the top to the bottom in the bore and a second longitudinal slot extending from the bottom and terminating within the first bushing; and
a keyed shaft extending into each of the boss and the first bushing, the keyed shaft comprising at least one protrusion that fits into the first longitudinal slot and the second longitudinal slot.
2 . The valve of claim 1 , further comprising:
a counterbore in the first bushing that is concentric with the bore.
3 . The valve of claim 1 ,
wherein the second longitudinal slot is angularly offset from the first longitudinal slot.
4 . The valve of claim 1 , further comprising:
a counterbore in the first bushing that is concentric with the bore and forms a bottom surface, wherein the
the second longitudinal slot begins at the surface of the counterbore.
5 . The valve of claim 1 , further comprising:
a second bushing on the plug that is spaced apart from the first bushing.
6 . The valve of claim 1 , further comprising:
a second bushing on the plug that is spaced apart from the first bushing, the second bushing having a longitudinal bore with splines disposed therein.
7 . The valve of claim 1 , further comprising:
a transverse slot in the keyed shaft.
8 . The valve of claim 1 , wherein the plug comprises a disc with a spherical sealing surface.
9 . The valve of claim 1 , wherein the plug comprises a disc with a spherical sealing surface and a leg that extends away from the disc and terminates at the first bushing.
10 . The valve of claim 1 , wherein the plug comprises a disc with a spherical sealing surface and a first leg and a second leg that extend away from the disc and terminate at the first bushing and a second bushing, respectively.
11 . A valve plug, comprising:
a disc;
a first leg and a second leg extending away from the disc; and
a first bushing and a second bushing disposed on a free end of the first leg and the second leg, respectively,
wherein the first bushing has a first end and a second end, and
wherein the first bushing comprises a first longitudinal bore with a first longitudinal slot and a second longitudinal slot,
wherein the first longitudinal slot extends from the first end to the second end, and
wherein the second longitudinal slot extends from the second end and terminates before the first end.
12 . The valve plug of claim 11 , further comprising:
a counterbore concentric with the first longitudinal bore.
13 . The valve plug of claim 11 , further comprising:
a second longitudinal slot that is angularly offset from the first longitudinal slot.
14 . The valve plug of claim 11 , further comprising:
a second longitudinal slot that is angularly offset from the first slot,
wherein the second longitudinal slot is shorter than the first longitudinal slot.
15 . The valve plug of claim 11 , wherein the second bushing has a second longitudinal bore with splines formed therein.
16 . The valve plug of claim 11 , wherein the disc forms a spherical sealing surface.
17 . A method, comprising:
providing a valve body with a boss disposed in an interior cavity, the boss having a bore;
providing a valve plug with a bushing having a top, a bottom, and a bore extending therethrough, the bore having a first longitudinal slot and a second longitudinal slot, the first longitudinal slot extended from the top to the bottom and the second longitudinal slot extending from the bottom and terminating between the top and the bottom;
securing the valve plug in the interior cavity with a keyed shaft that extends into part of the valve plug and the bore,
wherein the keyed shaft is rotatable in the valve plug so as to change position of a key member from a first position that allows the keyed shaft to exit from the valve plug to a second position that prevents the keyed shaft from exiting the valve plug.
18 . The method of claim 17 , wherein the second position prevents the valve plug from exiting the valve body.
19 . The method of claim 17 , wherein the second position prevents the valve plug from exiting the valve body but allows the valve plug to rotate relative to the bore in the boss.