Fluid handling – With leakage or drip collecting
Reexamination Certificate
2002-05-10
2004-02-24
Walton, George L. (Department: 3753)
Fluid handling
With leakage or drip collecting
C137S315010, C137S315270, C220S303000, C220S360000, C220S366100, C285S013000, C285S354000, C285S924000
Reexamination Certificate
active
06695000
ABSTRACT:
BACKGROUND
1. Field of the Invention
This invention relates generally to control valves and, more specifically, to the ability of a control valve to indicate loss of integrity of a sealed threaded joint therein, and to release internal pressure build-up within the control valve prior to disassembly of the control valve.
2. Description of the Prior Art
Notwithstanding the myriad of valves available for controlling the flow of fluid into or through a system, control valves have heretofore suffered from an inability (or poor ability) to indicate when there has been a loss of integrity of seals within the control valve. When a seal within a control valve fails, unless detected early, the resulting pressure loss in the system could lead to costly, and even dangerous consequences, particularly when highly flammable fluids are being passed through the control valve. Another shortcoming of existing control valves has been the inability to detect the presence of internal pressure within the valve during disassembly. If the internal pressure of the control valve is not released in a safe, controlled manner, the bonnet of the control valve could prematurely dislodge from the control valve, or an uncontrolled amount of fluid within or passing through the control valve could suddenly be released. This is why there are protocols for isolating and bleeding pressure out of control valves prior to disassembly. Nevertheless, it would be desirable for a control valve to provide an integral way to bleed its internal pressure prior to disassembly.
The manner in which these and other shortcomings of existing control valves are overcome is described in the following Summary of the Invention, Detailed Description of an Exemplary Embodiment, and the Drawings.
SUMMARY
In order to provide early detection of leakage in the seals within a control valve or in a bonnet of the control valve, the control valve is provided with an opening, or pressure bleed port, in the form of a bore in the body. The bonnet of the control valve is removably secured to the body of the control valve by a threaded interface. There is a seal between the bonnet and the interior wall of the body, in the immediate vicinity of a first end of the bore, or pressure bleed port, in the body. When there is an adequate pressure seal within the control valve, i.e. when there is no leakage present, none of the fluid whose flow rate is moderated by the control valve should be detected at the pressure bleed opening.
However, when there is a leaking seal within the control valve, the pressure differential between the atmosphere and the interior of the control valve causes some of the fluid in the control valve to leak out of the body of the control valve through the pressure bleed bore. The fluid exiting through the pressure bleed bore can then easily be detected, allowing a technician to observe there has been a seal failure between the body and the bonnet of the control valve.
Another useful purpose served by the passage through the valve body provided by the pressure bleed indicator port is the release of internal pressure within the control valve prior to disengaging the threaded connection between the bonnet and the valve body. If internal pressure builds up between the bonnet and valve body, such internal pressure needs to be relieved prior to disassembly. The pressure bleed indicator port exposes the interior of the control valve to the atmosphere as soon as the bonnet is unthreaded to a point at which it loses its seal with the valve body. At that point, the internal pressure of the control valve is released through the passageway (i.e., the inlet or outlet passageway of the control valve) immediately adjacent to the interior end, or second end, of the bleed bore, and travels through the bleed bore to the atmosphere, thereby equalizing with atmospheric pressure. Advantageously, the internal pressure is released prior to the bonnet being completely disengaged from its threaded connection with the body of the control valve.
REFERENCES:
patent: 2893435 (1959-07-01), Eichenberg
patent: 2943869 (1960-07-01), Nordin
patent: 3160427 (1964-12-01), Natho
patent: 3456679 (1969-07-01), Graham
patent: 3540760 (1970-11-01), Miller et al.
patent: 4072161 (1978-02-01), Schoeneweis et al.
patent: 4337788 (1982-07-01), Seger
patent: 4444220 (1984-04-01), Seger
patent: 4503878 (1985-03-01), Taylor
patent: 4705062 (1987-11-01), Baker
patent: 4801160 (1989-01-01), Barrington
patent: 4817994 (1989-04-01), Bronnert
patent: 4921281 (1990-05-01), Taylor
patent: 4923221 (1990-05-01), Taylor
patent: 4926898 (1990-05-01), Sampey
patent: 5065787 (1991-11-01), Lochmann
patent: 5241980 (1993-09-01), Corte
patent: 5590680 (1997-01-01), Gugala et al.
patent: 6269840 (2001-08-01), Beaver
patent: 905 566 (1954-03-01), None
patent: 1 381 927 (1975-01-01), None
Burr Ronald Charles
Hall Randy Jerold
Stiehl Mark Douglas
Fisher Controls International LLC
Marshall & Gerstein & Borun LLP
Walton George L.
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