US3714952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure relief valve
Assignee: Schneider Electric Systems USA Inc
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Filing: 1971-03-24
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Granted: 1973-02-06
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Expires: 1991-03-24
Abstract
Abstract An apparatus and method of relieving excess fluid pressure using a hydraulic cylinder to urge a hydraulic plug against a valve seat in communication with the fluid to be controlled. The hydraulic fluid used in the hydraulic cylinder is selected to have a compressibility at least as great as the compressibility of a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C to act as a liquid spring in response to excess fluid pressure. Also disclosed is the use of an air chamber in communication with the hydraulic fluid in the hydraulic cylinder which in combination with ordinary hydraulic fluid acts as a fluid spring.
Inventors
- 👤 E Bristol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:41
CPC Classifications
G; G05; G05B; G05B13/00; G05B13/02; G05B13/0205; G05B13/024; G05B11/00; G05B11/01; G05B11/32; Y; Y10; Y10T; Y10T137/00; Y10T137/0318
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
93 words
A pressure relief apparatus, for controlling fluid pressure, having a hydraulic cylinder for urging a valve plug against a valve seat comprising: a. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as the compressibility of a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and b. means for pressurizing the hydraulic cylinder with the hydraulic fluid.
Claim 2
Dependent Claim
93 words
A pressure relief apparatus, for controlling fluid pressure, having a hydraulic cylinder for urging a valve plug against a valve seat comprising: a. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as the compressibility of a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and b. means for pressurizing the hydraulic cylinder with the hydraulic fluid.
Claim 3
Dependent Claim
93 words
A pressure relief apparatus, for controlling fluid pressure, having a hydraulic cylinder for urging a valve plug against a valve seat comprising: a. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as the compressibility of a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and b. means for pressurizing the hydraulic cylinder with the hydraulic fluid.
Claim 4
Dependent Claim
93 words
A pressure relief apparatus, for controlling fluid pressure, having a hydraulic cylinder for urging a valve plug against a valve seat comprising: a. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as the compressibility of a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and b. means for pressurizing the hydraulic cylinder with the hydraulic fluid.
Claim 5
Dependent Claim
89 words
A pressure relief apparatus, for controlling fluid pressure, having a hydraulic cylinder for urging a valve plug against a valve seat comprising: a. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as 2 to 3 percent at 10,000 p.s.i. and 5 to 6 percent at 20,000 P.s.i. to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and b. means for pressurizing the hydraulic cylinder with the hydraulic fluid.
Claim 6
Dependent Claim
89 words
A pressure relief apparatus, for controlling fluid pressure, having a hydraulic cylinder for urging a valve plug against a valve seat comprising: a. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as 2 to 3 percent at 10,000 p.s.i. and 5 to 6 percent at 20,000 P.s.i. to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and b. means for pressurizing the hydraulic cylinder with the hydraulic fluid.
Claim 7
Dependent Claim
157 words
A pressure relief valve for controlling fluid pressure comprising: a. a valve seat in communication with a fluid under pressure; b. a hydraulic cylinder with a piston and piston rod, having a valve plug fastened to the end of the piston rod, mounted to move the valve plug against the valve seat and stop off the fluid when the piston rod is extended, and such that fluid pressure tends to move the valve plug away from the valve seat to relieve pressure and dump fluid; c. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as 2 to 3 percent at 10,000 p.s.i. and 5 to 6 percent at 20,000 p.s.i. to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and d. means for pressurizing the hydraulic cylinder with the hydraulic fluid to maintain a constant pressure.
Claim 8
Dependent Claim
157 words
A pressure relief valve for controlling fluid pressure comprising: a. a valve seat in communication with a fluid under pressure; b. a hydraulic cylinder with a piston and piston rod, having a valve plug fastened to the end of the piston rod, mounted to move the valve plug against the valve seat and stop off the fluid when the piston rod is extended, and such that fluid pressure tends to move the valve plug away from the valve seat to relieve pressure and dump fluid; c. a hydraulic fluid, for the hydraulic cylinder, having a compressibility at least as great as 2 to 3 percent at 10,000 p.s.i. and 5 to 6 percent at 20,000 p.s.i. to allow movement of the valve plug away from the valve seat in response to a pressure surge in the fluid to be controlled; and d. means for pressurizing the hydraulic cylinder with the hydraulic fluid to maintain a constant pressure.
Claim 9
Dependent Claim
29 words
A pressure relief valve as in claim 3, wherein the hydraulic fluid is a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C.
Claim 10
Dependent Claim
47 words
A pressure relief valve as in claim 3, wherein the means for pressurizing the hydraulic cylinder with the hydraulic fluid comprises: a hand operated hydraulic pump, a line running from the hydraulic pump to the hydraulic cylinder, and a check valve to maintain pressure of the fluid.
Claim 11
Dependent Claim
73 words
A pressure relief apparatus having a hydraulic cylinder for urging a valve plug against a valve seat to contain a fluid under pressure comprising: a. means for pressurizing the hydraulic cylinder with a hydraulic fluid and maintaining said pressure, and b. an air chamber in communication with the pressurized hydraulic fluid, to allow movement of the valve plug away from the valve seat in response to a pressure surge in the contained fluid.
Claim 12
Dependent Claim
73 words
A pressure relief apparatus having a hydraulic cylinder for urging a valve plug against a valve seat to contain a fluid under pressure comprising: a. means for pressurizing the hydraulic cylinder with a hydraulic fluid and maintaining said pressure, and b. an air chamber in communication with the pressurized hydraulic fluid, to allow movement of the valve plug away from the valve seat in response to a pressure surge in the contained fluid.
Claim 13
Dependent Claim
40 words
A pressure relief apparatus as in claim 6, wherein the means for pressurizing and maintaining pressure in the hydraulic cylinder comprises: a hand operated hydraulic pump, a check valve, and a line communicating between the pump and the hydraulic cylinder.
Claim 14
Dependent Claim
39 words
A pressure relief apparatus as in claim 7, further comprising: a hydraulic fluid having compressibility at least as great as the compressibility of a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C.
Claim 15
Independent Claim
82 words
A method of relieving fluid pressure utilizing a hydraulic cylinder to urge a valve plug against a valve seat in communication with fluid to be controlled, wherein the steps comprise: a. introducing a hydraulic fluid, having a compressibility of at least 2 to 3 percent at 10,000 p.s.i. and of at least 5 to 6 percent at 20,000 p.s.i. into the hydraulic cylinder to urge the valve plug against the valve seat; and b. maintaining a constant pressure on the hydraulic fluid.
Claim 16
Independent Claim
82 words
A method of relieving fluid pressure utilizing a hydraulic cylinder to urge a valve plug against a valve seat in communication with fluid to be controlled, wherein the steps comprise: a. introducing a hydraulic fluid, having a compressibility of at least 2 to 3 percent at 10,000 p.s.i. and of at least 5 to 6 percent at 20,000 p.s.i. into the hydraulic cylinder to urge the valve plug against the valve seat; and b. maintaining a constant pressure on the hydraulic fluid.
Claim 17
Independent Claim
89 words
A method of relieving fluid pressure utilizing a hydraulic cylinder to urge a valve plug against a valve seat in communication with fluid to be controlled, wherein the steps comprise: a. utilizing a hydraulic fluid from materials having a compressibility at least as great as a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C; b. pumping the hydraulic fluid into the hydraulic cylinder with a hand operated pump until reaching the desired pressure; and c. maintaining the pressure in the hydraulic fluid.
Claim 18
Independent Claim
89 words
A method of relieving fluid pressure utilizing a hydraulic cylinder to urge a valve plug against a valve seat in communication with fluid to be controlled, wherein the steps comprise: a. utilizing a hydraulic fluid from materials having a compressibility at least as great as a paraffinic base mineral oil having a viscosity of about 20 to 50 centipoises at 25*C; b. pumping the hydraulic fluid into the hydraulic cylinder with a hand operated pump until reaching the desired pressure; and c. maintaining the pressure in the hydraulic fluid.
Claim 19
Independent Claim
82 words
A method of relieving fluid pressure utilizing a hydraulic cylinder to urge a valve plug against a valve seat in communication with fluid to be controlled, wherein the steps comprise: a. Placing an air chamber such that the air chamber will be in communication with hydraulic fluid that may be introduced into the hydrAulic cylinder; b. pressurizing the hydraulic cylinder with hydraulic fluid to hold the valve plug against the valve seat; and c. maintaining a constant pressure on the hydraulic fluid.
Claim 20
Independent Claim
82 words
A method of relieving fluid pressure utilizing a hydraulic cylinder to urge a valve plug against a valve seat in communication with fluid to be controlled, wherein the steps comprise: a. Placing an air chamber such that the air chamber will be in communication with hydraulic fluid that may be introduced into the hydrAulic cylinder; b. pressurizing the hydraulic cylinder with hydraulic fluid to hold the valve plug against the valve seat; and c. maintaining a constant pressure on the hydraulic fluid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |