Fluid handling – Systems – Flow path with serial valves and/or closures
Reexamination Certificate
1999-03-01
2001-09-04
Lee, Kevin (Department: 3753)
Fluid handling
Systems
Flow path with serial valves and/or closures
C251S282000, C137S625300
Reexamination Certificate
active
06283152
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to flow control devices. More particularly, the invention relates to a control valve having multiple seals in a single valve trim. In a particular embodiment, the invention relates to a choke valve having multiple balanced sealing sleeves contained within a single valve trim.
2. Background of the Related Art
Flow control devices are useful for modifying the flow rate in flow channels, conduits or systems. For example, flow control choke valves are useful in fluid pipelines, such as high pressure oil and gas production pipelines where high pressure differentials may exist between the fluid pressure in the upstream and downstream pipelines, between which the valve is disposed. For example, the upstream fluid pressure in a high pressure oil and gas production pipeline may be on the order of 5000 pounds per square inch and the downstream fluid pressure ranging from 0 to 5000 pounds per square inch. Thus, flow control devices may be designed to be capable of operating in high pressure environments.
Flow control devices typically include a reciprocating valve stem threadably or otherwise connected to a valve body. The valve stem carries or is connected to a closure member or a sealing assembly. As it reciprocates, the typical valve stem is capable of engaging and disengaging the closure member with a valve seat (or around an orifice). Fluid pressure within the flow control device may, however, exert undesirable pressure forces on the internal components of the flow control device that are in contact with the flowing fluid, mixture or other media (the valve “trim”) and which are associated or connected with the valve stem. This can make reciprocation or movement of the valve stem and thus operation of the flow control device difficult or impossible.
Balanced flow control devices have been contemplated to balance pressure forces on internal components of the flow control device in an effort to reduce or eliminate the resultant pressure forces on the valve stem. To achieve balanced valve trim, balance conduits extending at least partially through one or more internal valve components may be provided. For example, one or more balance conduits may be disposed in the closure member of a fluid control valve. In such example, fluid and thus fluid pressure from the downstream bore can be communicated through the balance conduit(s) to opposing sides or surfaces of the closure member, enabling the closure member to be balanced.
Existing balanced flow control devices include a single balanced closure member or sealing assembly with a single seal in each valve trim. However, for a variety of reasons, it is believed that it would be beneficial to provide one or more additional seals within the same valve trim as that of the single seal. For example, this may be used to provide resilient secondary sealing in the event that the primary non-resilient seal member should fail. Existing balanced control valves are not believed to provide multiple seals or seal members within a single valve trim. In addition, existing balanced control valves do not provide for multiple balanced sealing assemblies.
Accordingly, theres is a need for a flow control valve with multiple sealing assemblies, or seals, within a single valve trim. Ideally, at least in some instances, each of the seals, or multiple sealing assemblies, of such a flow control valve could be balanced. Further, especially well received would be a valve having such feature(s) and which is useful as a choke valve.
SUMMARY OF THE INVENTION
In a particular aspect, a balanced control valve includes: a choke body having an upstream bore, a downstream bore, a fluid flow chamber, and a valve seat for sealing the fluid flow chamber from the downstream bore; a bonnet connected to the choke body and adapted to receive a valve stem therethrough; and a valve stem disposed through the bonnet and having a plurality of balanced sealing assemblies operably connected thereto. In such an embodiment, the plurality of balanced sealing assemblies may comprise an inner sealing assembly and an outer sealing assembly. The inner sealing assembly may have a balance conduit passing therethrough for communicating downstream fluid pressure with the balance chamber of the inner sealing assembly, and the inner sealing assembly may include an inner sealing sleeve with a sealing member for sealing engagement with an inner sealing surface of the valve seat of the choke body.
The sealing member of the inner sealing sleeve may be a non-resilient sealing surface, which could be a carbide tip. Further, the outer sealing assembly may have a balance conduit passing therethrough for communicating downstream fluid pressure with the balance chamber of the outer sealing assembly, and the outer sealing assembly may include an outer sealing sleeve with a sealing member for sealing engagement with an outer sealing surface of the valve seat of the choke body. The sealing member of the outer sealing sleeve may be a resilient seal ring, which could be an o-ring.
In another aspect, a control valve includes a plurality of sealing assemblies in a single choke trim. In such an embodiment, each of the plurality of sealing assemblies may be a balanced sealing assembly. The plurality of sealing assemblies may comprise: an outer sealing assembly having a sealing member adapted for sealing engagement with an outer sealing surface of a valve seat associated with the choke valve, and also having a balance conduit therethrough for communicating downstream fluid pressure to a balance chamber associated with the outer sealing assembly; and an inner sealing asssembly in sliding engagement with the outer sealing assembly, and having a sealing member adapted for sealing engagement with an inner sealing surface of the valve seat, and also having a balance conduit therethrough for communicating downstream fluid pressure to a balance chamber associated with the inner sealing assembly.
The outer sealing assembly may include a fluid flow conduit therethrough for communicating fluid pressure from a fluid flow chamber within the choke valve to a chamber within the outer sealing assembly associated with the inner sealing assembly. Further, the sealing member of the outer sealing assembly may be a resilient sealing member, and the sealing member of the inner sealing assembly may be a non-resilient sealing member. The plurality of sealing assemblies may be selectively reciprocated between a first, fully open position; a second, initially engaged position; and a third, fully engaged position. Further, in the fully open position, neither the inner sealing assembly nor the outer sealing assembly is sealingly engaged with the valve seal. In the initially engaged position, the inner sealing assembly is sealingly engaged with the valve seat but the outer sealing assembly may be sealingly engaged with the valve seat. In the fully engaged position, the inner and outer sealing assemblies may be sealingly engaged with the valve seat.
REFERENCES:
patent: 4240609 (1980-12-01), Hahn et al.
patent: 4569370 (1986-02-01), Witt
patent: 4735229 (1988-04-01), Lancaster
patent: 4905733 (1990-03-01), Carow
patent: 4971099 (1990-11-01), Cyvas
patent: 5072749 (1991-12-01), Ligh
patent: 5076324 (1991-12-01), Herman et al.
patent: 5086808 (1992-02-01), Pettus
patent: 5277225 (1994-01-01), Smith
Corte Kane J.
Corte, Jr. Bobby J.
Cor-Val, Inc.
Lee Kevin
Smith E. Randall
LandOfFree
Multiple sleeve valve assembly does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Multiple sleeve valve assembly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiple sleeve valve assembly will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2517184