Valve stem extension

Details Valve stem extension Valve stem extension

1999-05-26

2001-07-10

Shaver, Kevin (Department: 3754)

Valves and valve actuation

Limit stop

Rotary valve

C251S292000, C251S293000, C403S320000, C411S383000, C411S522000

Reexamination Certificate

active

06257551

ABSTRACT:

BACKGROUND OF THE INVENTION
The invention relates to a valve stem extension for extending a valve stem.
A typical prior art valve
10
, such as a ball valve or plug valve, is illustrated in FIG.
1
. Valve
10
includes a valve body
12
defining an inlet
14
and an outlet
16
. A ball or plug (not shown) located within body
12
is movable between a first position which blocks flow through valve
10
, and a second position which allows flow through valve
10
. Attached to the ball or plug and extending from body
12
is a valve stem
18
. A packing nut
19
compresses a teflon seal (not shown) underneath nut
19
, forming a seal between valve stem
18
and body
12
.
The ball or plug is moved by rotating valve stem
18
. Valve stem
18
includes two opposing flat sides
24
a
,
24
b
, and two opposing circumferential threaded sides
26
a
,
26
b
. A handle
20
attached to valve stem
18
is used to rotate valve stem
18
. Handle
20
defines an oblong opening
28
which includes two opposing flat sides
30
a
,
30
b
for engaging the opposing flat sides
24
a
,
24
b
of valve stem
18
. A top nut
32
is threaded onto valve stem
18
, threadingly engaging the opposing circumferential threaded sides
26
a
,
26
b
of valve stem
18
, to secure handle
20
to valve stem
18
.
Valve body
12
includes rotation limiting flanges
34
a
,
34
b
, which define rotation limiting surfaces
35
a
,
35
b
. Handle
20
has a stub
36
. Rotation of handle
20
is limited by abutment of stub
36
against rotation limiting surfaces
35
a
,
35
b.
SUMMARY OF THE INVENTION
It is often desirable to cover a system of piping with insulation, both to protect the piping and components and to conserve energy. Covering the piping system with insulation can affect access to the valve stem (if the valve is covered). If the valve is left exposed for access to the valve stem, insulation and protection performance can be impaired.
In one aspect, the invention features a valve stem extension for extending the length of a valve stem to permit access to the valve stem. The valve stem extension includes an extension member and a rotation resisting member. The extension member has a first end for engaging the valve stem and defines an opening which exposes two opposing flat sides of the valve stem when the extension member is engaged with the valve stem. The rotation resisting member includes two opposing flat sides and is configured to be insertable within the opening of the extension member after engagement of the extension member with the valve stem. When positioned in the opening, the two opposing flat sides of the rotation resisting member engage the two opposing flat sides of the valve stem to resist rotation of the extension member relative to the valve stem.
Embodiments of this aspect of the invention may include one or more of the following features. The valve stem includes two opposing circumferential threaded sides, and the first end of the extension member includes a threaded bore for threaded engagement with the valve stem. The extension member includes a second end including two opposing flat sides and two opposing circumferential threaded sides. The rotation resisting member is a C-shaped insert, and the opening of the extension member has a corresponding C-shape for receiving the C-shaped insert. The valve stem extension includes a bushing defining a bore for receiving the extension member. An outer housing defines a bore for receiving the extension member. The bushing acts to maintain the rotation resisting member within the opening of the extension member. The outer housing defines an anti-rotation opening and includes upper rotation limiting flanges.
In another aspect, the invention features a valve including a valve body having a flow inlet and a flow outlet. A flow control device is movable between a first position which blocks flow through the valve body and a second position which allows flow through the valve body. A rotatable valve stem is connected to the flow control device for moving the flow control device between the first and second positions. The valve includes a valve stem extension having an extension member and a rotation resisting member. The extension member has a first end for engaging the valve stem and defines an opening which exposes two opposing flat sides of the valve stem when the extension member is engaged with the valve stem. The rotation resisting member includes two opposing flat sides and is configured to be insertable within the opening of the extension member after engagement of the extension member with the valve stem. When positioned in the opening, the two opposing flat sides of the rotation resisting member engage the two opposing flat sides of the valve stem to resist rotation of the extension member relative to the valve stem.
Embodiments of this aspect of the invention may include one or more of the following features. The extension member includes a second end having two opposing flat sides. The valve further includes a valve handle for engaging the second end of the extension member. The valve handle defines an opening including two opposing flat sides for engaging the two opposing flat sides of the second end of the extension member. The valve handle also includes a rotation limiting stub for limiting the rotation of the valve handle, and the valve housing includes a rotation limiting flange. The valve stem extension further includes an outer housing defining an anti-rotation opening for receiving the rotation limiting flange of the valve housing.
In another aspect, the invention features a method for extending a valve stem. The method includes attaching a valve stem extension member to the valve stem. The extension member includes a first end for engaging the valve stem and defines an opening which exposes two opposing flat sides of the valve stem when the extension member is engaged with the valve stem. A rotation resisting member is inserted into the opening of the extension member. The rotation resisting member includes two opposing flat sides for engaging the two opposing flat sides of the valve stem to resist rotation of the extension member relative to the valve stem.
Embodiments of this aspect of the invention may include one or more of the following features. A bushing is placed over the extension member and the rotation resisting member to maintain the rotation resisting member within the opening of the extension member. An outer housing is placed over the bushing. A second end of the extension member is engaged by a valve handle. The second end of the extension member includes two opposing flat sides and the valve handle defines an opening including two opposing flat sides for engaging the two opposing flat sides of the second end of the extension member.


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patent: 5275200 (1994-01-01), Yamamoto
patent: 5579804 (1996-12-01), Roberts
patent: 5636540 (1997-06-01), Myers
patent: 5954088 (1999-09-01), Huang

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