Fluid handling – With repair – tapping – assembly – or disassembly means – Pressure regulating type valve
Reexamination Certificate
2002-04-29
2003-12-30
Walton, George L. (Department: 3753)
Fluid handling
With repair, tapping, assembly, or disassembly means
Pressure regulating type valve
C137S315010, C137S315270, C137S469000, C137S494000, C137S542000, C251S333000, C251S361000, C251S362000, C251S363000, C251S367000, C251S368000
Reexamination Certificate
active
06668853
ABSTRACT:
BACKGROUND
This application discloses a pressure relief valve of the type usable on vessels for containing highly corrosive chemicals. Such valves may be used on railway tank cars or other transportation or storage vessels.
For various reasons, railway industry standards set by the AAR currently require that, aside from O-rings and other seals, the materials for construction of pressure relief valves be metallic. For example, parts connected directly to the vessel wall may undergo substantial bending or tensile stresses in use. Typically, the parts of such pressure relief valves which may be “wetted” by, i.e., exposed to contact with, the lading in use, are formed of metals exhibiting high corrosion resistance, such as stainless steel, zirconium, and alloys such as those sold under the trademarks MONEL and HASTELLOY, all of which are quite costly. Furthermore, parts made of such metals heretofore have had to be fabricated by casting, resulting in significant porosity. While some materials, such as zirconium have recently become available in less porous bar stock, it is still quite expensive.
Less costly materials which afford adequate corrosion resistance, such as certain plastics, are known, but have heretofore not been permitted in pressure relief valves for railway tank cars because they have lacked sufficient tensile or bending strength and/or fire-resistance to be used in the “wetted” parts of current pressure relief valve designs.
In prior pressure relief valve designs, the main valve body has been of unitary one-piece metal construction. Thus, while only portions of such valve bodies may be exposed to corrosive chemicals in use, repair of corrosion damage has entailed replacing the entire body, or returning the valve to the manufacturer for remachining and/or recoating of the valve body, since such procedures cannot be performed in the field.
SUMMARY
This application discloses a pressure relief valve which avoids the disadvantages of prior valve designs, while affording additional structural and operating advantages.
An important aspect is the provision of a pressure relief valve for use in highly corrosive environments which is of simpler and more economical construction that current designs.
Another aspect is the provision of a pressure relief valve of the type set forth, which has parts exposed to highly corrosive ladings in use which can, nevertheless, be safely formed of non-metallic materials.
In connection with the foregoing aspect, another aspect is the provision of a pressure relief valve of the type set forth, wherein the parts of the valve exposed to corrosive ladings are subjected to minimized tensile or bending stresses.
A still further aspect is the provision of a pressure relief valve of the type set forth, wherein the parts exposed in use to corrosive ladings are relatively easily field-replaceable.
REFERENCES:
patent: 2226732 (1940-12-01), McBride
patent: 2335829 (1943-11-01), McBride
patent: 2507851 (1950-05-01), Bryant et al.
patent: 2628633 (1953-02-01), Folmsbee
patent: 2657897 (1953-11-01), Folmsbee
patent: 2695032 (1954-11-01), Kmiecik
patent: 2740425 (1956-04-01), Garland
patent: 2853097 (1958-09-01), Davis
patent: 2875978 (1959-03-01), Kmiecik
patent: 2910998 (1959-11-01), Davis
patent: 2939479 (1960-06-01), Gilmore
patent: 2979067 (1961-04-01), Kern, Jr. et al.
patent: 3006361 (1961-10-01), Reinemann
patent: 3067769 (1962-12-01), Skulley
patent: 3104673 (1963-09-01), Kirsch
patent: 3123092 (1964-03-01), Kmiecik et al.
patent: 3361154 (1968-01-01), Alexandre
patent: 3461905 (1969-08-01), McCabe
patent: 3605793 (1971-09-01), Kinsel
patent: 3872875 (1975-03-01), Raidl, Jr.
patent: 3970280 (1976-07-01), Kunz
patent: 4040442 (1977-08-01), Alexandre
patent: 4201242 (1980-05-01), Troxell, Jr.
patent: 4440189 (1984-04-01), Graham
patent: 4485843 (1984-12-01), Wolff
patent: 4532958 (1985-08-01), Napolitano
patent: 4674530 (1987-06-01), Bickford
patent: 4799506 (1989-01-01), Taylor
patent: 4932434 (1990-06-01), Taylor
patent: 5333635 (1994-08-01), Higgins et al.
patent: 5503180 (1996-04-01), Nimberger
patent: 5644930 (1997-07-01), Albertson et al.
patent: 5678604 (1997-10-01), Plauborg et al.
patent: 5738333 (1998-04-01), Cognevich et al.
patent: 5855225 (1999-01-01), Williams, III
patent: 6209561 (2001-04-01), Kugelev et al.
Delaware Capital Formation Inc.
Seyfarth Shaw LLP
Walton George L.
LandOfFree
Pressure relief valve with field-replaceable high... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pressure relief valve with field-replaceable high..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pressure relief valve with field-replaceable high... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3105491