Fluid handling – With repair – tapping – assembly – or disassembly means – With mechanical movement between actuator and valve
Utility Patent
1998-10-27
2001-01-02
Walton, George L. (Department: 3753)
Fluid handling
With repair, tapping, assembly, or disassembly means
With mechanical movement between actuator and valve
C137S315280, C251S214000, C251S264000, C251S274000, C251S368000
Utility Patent
active
06167902
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bottom entry valve for use with fluid at cryogenic temperatures.
2. Description of Related Art
High performance valves, particularly for use at cryogenic temperatures, require precisely fabricated internal valve components to ensure proper closure of the valve without the likelihood of leakage. Thus, it is often necessary to have easy access to the internal valve components for repairs and other maintenance. Cryogenic valves also face an increased possibility of cryogens escaping through relatively small openings due to substantial shrinkage of the valve components when subjected to cryogenic temperatures.
Traditionally, bottom entry valves have been developed to provide ready access to the internal valve components without the need to physically remove the entire valve from the fluid line or piping. Typically, a bottom entry valve involves an assembled valve body which once constructed results in a unit with a top end, a bottom entry end and a main body section. The use of several components with their related seals and means of assembly such as welding and brazing increases the possibility of leaks.
The top end of the valve body is provided with an opening, the bottom entry end of the valve body is also provided with an opening. The top end opening is sized and shaped to permit the top portion of the valve stem to extend therethru. A hand wheel is usually attached to the top end of the valve stem. The top end of the valve body is typically sealed with a removable bonnet nut acting in conjunction with a system of springs, packing set and bearing. The bottom entry end opening is sized to be relatively large. The bottom entry end opening is sealed with a removable body ring acting in conjunction with a gasket. At a predetermined position on the main body section of the valve an inlet and an outlet are provided. The valve stem supports the valve seal member and seal nut. The valve seal member acts to permit a flow of fluid from the inlet to the outlet when the valve stem is in a first or open position and prohibits any flow when the valve stem is in a second or closed position. The valve seal member acts as a seal when the valve stem is in the second or closed position. The valve seal member is secured in a desired position by the seal nut. A valve stem bearing is provided to permit easy rotation of the valve stem and also to insure that the valve stem does not make contact with the interior of the valve body. A retaining ring is provided to keep the valve stem bearing in a desired position. The valve stem bearing and retaining ring are supported by the valve body. The size of the bottom entry end opening is large enough to permit the valve stem, valve seal member, seal nut, valve stem bearing and retaining ring to be installed and removed. In the traditional bottom entry valves that are available, in order to perform maintenance, it is necessary to first remove the valve stem together with the valve seal member and seal nut from within the valve body, then remove the retaining ring and the valve stem bearing from within the valve body. The removal of all of these internal components of the valve involve several steps. It may be necessary to remove all of the components in order to remove the one component that is causing a problem. In the existing art the removal of the stem and related components is performed in order that a malfunction be corrected. This means that the valve is still connected to the fluid line or piping. In order to remove the retaining ring or valve stem bearing special tools are required. The use of tools to remove these items may cause damage to the valve body sealing surfaces resulting in leaks.
The present invention provides an improved bottom entry cryogenic valve.
One of the objects of the invention is to provide an improved bottom entry cryogenic valve that has a single unit valve body with no brazements or weldments.
Another object of the invention is to provide an improved bottom entry valve that combines the seal nut, retaining ring and valve stem bearing into a seal nut/bearing, reducing the number of internal components.
A further object of the invention is to provide an improved bottom entry cryogenic valve that has the valve seal member, and seal nut/bearing supported on the valve stem.
A still further object of the invention is to provide an improved bottom entry cryogenic valve that allows for removal of the valve stem, valve seal member and seal nut/bearing as a unit.
An additional object of the invention is to provide an improved bottom entry cryogenic valve that eliminates leakage by utilizing a one piece cast body. When combined with a valve stem that supports the valve seal and seal nut/bearing easy removal is accomplished in one step for repair or replacement.
The one piece body can be cast so that the inlet and outlet extensions are long enough to insulate the soft seals in the valve from heat generated when the complete valve is welded into the pipeline.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.
SUMMARY OF THE INVENTION
This is an improved bottom entry valve for use at cryogenic temperatures. In the present invention the housing for the valve is formed by a single piece cast body. The single piece cast body eliminates the welding or brazing of several connections. In addition the present invention combines the seal nut, retaining ring and valve stem bearing into a single member entitled seal nut/bearing. The present invention further provides that the valve stem supports the valve seal and the seal nut/bearing. By having the seal nut/bearing supported by the valve stem the invention allows for removal of the valve stem, valve seal member and seal nut/bearing in one step as a unit. In addition the seal nut/bearing has greater surface areas in contact with both the valve stem and the internal sealing surface of the single piece cast body. These improvements to the bottom entry cryogenic valve substantially reduce the possibility of leakage and in addition provides for a quick, easy and more efficient removal of the valve stem, valve seal member and seal nut/bearing for repair or replacement. The result is a significant reduction of downtime for the valve during repair or replacement of the valve stem, valve seal member or seal nut/bearing. The removal of the valve stem and parts supported thereon further allows for complete inspection of the internal sealing surfaces of the single unit cast valve body.
The single piece cast body is preferably made of austenitic stainless steel. The typical valve stem bearing is made of bronze, the typical retaining ring is made of beryllium copper and a typical valve seal member nut is made of brass. In the present invention the seal nut/bearing that replaces the seat nut, retaining ring and valve stem bearing is made of free cutting brass. Obviously other materials suitable for use at cryogenic temperatures may be used for the seal nut/bearing. The seal nut/bearing is supported by the mid portion of the valve stem. The seal nut/bearing acts to insure that the mid portion of the valve stem does not make contact with the internal surfaces of the single piece cast valve body. The seal nut/bearing is formed in the shape of an elongated tubular member. The seal nut/bearing is formed as a cylinder and has an internal surface with two portions, the top portion and the bottom or nut portion. The top portion having a diameter that is sized and shaped to permit the valve stem to support the seal nut/bearing securely. The bottom or nut portion has formed threads with an outside flange. The threads are sized to engage with threads on the mid portion of the valve stem. The seal nut/bearing outer surface has four sections, the top bearing section, the mid sleeve section, the nut section and a flange section. The seal nut/bearing outer surface sections are sized
Baird, Esq. James F.
Walton George L.
LandOfFree
Bottom entry cryogenic valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bottom entry cryogenic valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bottom entry cryogenic valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2505237