External valve operating means
First Claim
1. External valve operating means for operating a valve maintained under internal pressure and having a valve body and a rotatable valve stem, which comprises:
- a hollow adjustable and removable operating seal cap having a top opening and a bottom opening and wherein the inner surface has threads for threaded engagement with the valve body;
an external valve stem drive having a lower end in mating operative engagement with an upper portion of said valve stem, said external valve stem drive having an upper end protruding through said top opening of said operating seal cap, said upper end of said external valve stem drive being shaped to be engaged by a tool whereby said valve stem may be rotated to operate the valve;
a first O-ring seal disposed between the lower end of said external valve stem drive and said operating seal cap in the proximity of said top opening so as to form a seal therebetween which is maintained by any unvented internal valve pressure;
a second O-ring seal disposed between a lower portion of said operating seal cap and said valve body adjacent said threaded engagement; and
means for venting said external valve operating means whereby said operating seal cap is movable along said lower end of said external valve stem drive and the portion of said valve body adjacent said threaded engagement to allow partial disengagement of said threaded engagement so that said venting means is established between said seal cap and said valve body when said second seal is in a non-sealing engagement with said valve body for venting internal pressure within said external valve operating means before removal thereof.
5 Assignments
0 Petitions
Accused Products
Abstract
An external valve operating means that forms a seal around the rotating valve stem of a valve operating under internal pressure is disclosed. This seal prevents the escape of fluids should the valve'"'"'s primary seals fail. The external valve operating means allows for rotation of the valve stem without removal or compromise of the seal. A stationary operating seal cap is in threaded and sealed engagement with the valve body. Upon partial disengagement of the stationary operating seal cap, the pressure within the external valve operating means is vented. An external valve stem drive protrudes through the top of the stationary operating seal cap. An O-ring forms a seal between the two. The bottom of the external stem drive mates with the rotating valve stem while the top of the external stem drive is shaped so as to allow gripping by a tool. Rotation of the external stem drive via the tool effects rotation of the valve stem while the seal surrounding it is maintained.
31 Citations
5 Claims
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1. External valve operating means for operating a valve maintained under internal pressure and having a valve body and a rotatable valve stem, which comprises:
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a hollow adjustable and removable operating seal cap having a top opening and a bottom opening and wherein the inner surface has threads for threaded engagement with the valve body; an external valve stem drive having a lower end in mating operative engagement with an upper portion of said valve stem, said external valve stem drive having an upper end protruding through said top opening of said operating seal cap, said upper end of said external valve stem drive being shaped to be engaged by a tool whereby said valve stem may be rotated to operate the valve; a first O-ring seal disposed between the lower end of said external valve stem drive and said operating seal cap in the proximity of said top opening so as to form a seal therebetween which is maintained by any unvented internal valve pressure; a second O-ring seal disposed between a lower portion of said operating seal cap and said valve body adjacent said threaded engagement; and means for venting said external valve operating means whereby said operating seal cap is movable along said lower end of said external valve stem drive and the portion of said valve body adjacent said threaded engagement to allow partial disengagement of said threaded engagement so that said venting means is established between said seal cap and said valve body when said second seal is in a non-sealing engagement with said valve body for venting internal pressure within said external valve operating means before removal thereof. - View Dependent Claims (2, 3, 4, 5)
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Specification