Patent US3823734A successfully refreshed from Google Patents.
US3823734A
Expired / Lapsed
US
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Area ratio excess flow shutoff valve system
Assignee: Individual
•
Filing: 1973-05-21
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Granted: 1974-07-16
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Expires: 1993-05-21
Abstract
Abstract A spool of a normally open valve has an orificed passage for gas flow from a source chamber to a control pressure chamber. The spool has an area facing control pressure which exceeds the area of the spool facing source pressure. The spool is kept in its open position during normal operation because the product of control chamber pressure and spool area seeing the control chamber and normal to the axis of the spool is maintained equal to or greater than the product of source pressure and spool area seeing source pressure and normal to the axis of the spool. Downstream from the control pressure chamber, a second orifice maintains the pressure in the control pressure chamber during normal operation at a value great enough to keep the spool control area control chamber pressure product high enough to keep the valve open. When there is a leak, however, between the valve and the second orifice, the second orifice cannot maintain a sufficiently high control pressure and the product of source pressure and spool source area will exceed the offsetting product and the spool will move to a closed position preventing gas flow through the valve. The orifice in the spool assures that there will be sufficient pressure drop between the two chambers to cause the spool to close.
Inventors
- 👤 Jones R Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:23
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/20; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7784; Y10T137/7785; Y10T137/7787; Y10T137/7788; Y10T137/7791
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
279 words
An area ratio excess flow shutoff valve comprising: a. a body having a source chamber, a conTrol chamber, means for communicating the source chamber with a source of pressurized gas, and means for communicating the control chamber with a downstream orifice; b. means defining a passage between the source chamber and the control chamber; c. means defining an upstream orifice in the passage; d. a valving element disposed in the body for displacement between an open position allowing fluid to flow through the passage from the source chamber to the control chamber and a closed position preventing such gas flow through the passage, the valving element having a control area exposed to pressure in the control chamber for control pressure to act against in a direction tending to displace the element into its open position, and a source area exposed to pressure in the source chamber for source pressure to act against in a direction tending to displace the element into its closed position, the area of the control area exceeding that of the source area; and e. the control area excess over the source area being such that pressure in the source chamber will force the valving element into its closed position only when there is a leak between the shutoff valve and the downstream orifice, the downstream orifice without a leak maintaining pressure in the control chamber sufficiently high to keep the valving element in its open position, the upstream orifice providing a pressure drop from the source chamber to the control chamber when there is a leak which is suficient to allow pressure in the source chamber to force the valving element into its closed position.
Claim 2
Dependent Claim
279 words
An area ratio excess flow shutoff valve comprising: a. a body having a source chamber, a conTrol chamber, means for communicating the source chamber with a source of pressurized gas, and means for communicating the control chamber with a downstream orifice; b. means defining a passage between the source chamber and the control chamber; c. means defining an upstream orifice in the passage; d. a valving element disposed in the body for displacement between an open position allowing fluid to flow through the passage from the source chamber to the control chamber and a closed position preventing such gas flow through the passage, the valving element having a control area exposed to pressure in the control chamber for control pressure to act against in a direction tending to displace the element into its open position, and a source area exposed to pressure in the source chamber for source pressure to act against in a direction tending to displace the element into its closed position, the area of the control area exceeding that of the source area; and e. the control area excess over the source area being such that pressure in the source chamber will force the valving element into its closed position only when there is a leak between the shutoff valve and the downstream orifice, the downstream orifice without a leak maintaining pressure in the control chamber sufficiently high to keep the valving element in its open position, the upstream orifice providing a pressure drop from the source chamber to the control chamber when there is a leak which is suficient to allow pressure in the source chamber to force the valving element into its closed position.
Claim 3
Dependent Claim
15 words
The shutoff valve claimed in claim 1 wherein the passage is in the valving element.
Claim 4
Dependent Claim
49 words
The shutoff valve claimed in claim 1 wherein the valving element is disposed for translation in the body and has a head in the control chamber, and a shank extending from the head towards the source chamber and disposed in a bore of the body between the two chambers.
Claim 5
Dependent Claim
43 words
The shutoff valve claimed in claim 3 wherein the passage opens into the source chamber radially of the axis of the shank and is closed to the source chamber by being within the bore when the valving element is in its closed position.
Claim 6
Dependent Claim
30 words
The shutoff valve claimed in claim 4 including means to prevent gas flow from the source chamber to the control chamber along the interface between the shank and the bore.
Claim 7
Dependent Claim
54 words
The shutoff valve claimed in claim 3 wherein the body has a vent passage between the control chamber and atmosphere and opening into the control chamber at the head, and including means to prevent communication between the vent passage on the one hand and the source chamber and the control chamber on the other.
Claim 8
Dependent Claim
260 words
An area ratio excess flow shutoff valve and system comprising: a. a gas circuit including a downstream orifice; b. a valve in the gas circuit upstream from the downstream orifice, the valve having a control chamber in series with the downstream orifice, pressure in the control chamber being maintained above a predetermined minimum by the downstream orifice, a source chamber adapted to receive a gas under pressure, a passage serially connecting the two chambers, an upstream orifice in the passage for creating a pressure drop between the two chambers, and a valving element disposed for displacement between an open position permitting gas flow through the passage and a closed position preventing such flow; c. the valving element having a control area disposed for pressure in the control chamber to urge the valving element into its open position, and a source area disposed for pressure in the source chamber to urge the valving element into its closed position; d. the control area exceeding the source area by an amount sufficient for pressure in the control chamber to maintain the valving element in its open position by pressure maintained by the downstream orifice in the control chamber; and e. the amount that the control area exceeds the source area being limited such that when a leak occurs between the doWnstream orifice and the control chamber, pressure in the source chamber will force the valving element into its closed position, the upstream orifice assuring, when a leak occurs, a sufficient drop in pressure in the control chamber for the valving element to close.
Claim 9
Dependent Claim
260 words
An area ratio excess flow shutoff valve and system comprising: a. a gas circuit including a downstream orifice; b. a valve in the gas circuit upstream from the downstream orifice, the valve having a control chamber in series with the downstream orifice, pressure in the control chamber being maintained above a predetermined minimum by the downstream orifice, a source chamber adapted to receive a gas under pressure, a passage serially connecting the two chambers, an upstream orifice in the passage for creating a pressure drop between the two chambers, and a valving element disposed for displacement between an open position permitting gas flow through the passage and a closed position preventing such flow; c. the valving element having a control area disposed for pressure in the control chamber to urge the valving element into its open position, and a source area disposed for pressure in the source chamber to urge the valving element into its closed position; d. the control area exceeding the source area by an amount sufficient for pressure in the control chamber to maintain the valving element in its open position by pressure maintained by the downstream orifice in the control chamber; and e. the amount that the control area exceeds the source area being limited such that when a leak occurs between the doWnstream orifice and the control chamber, pressure in the source chamber will force the valving element into its closed position, the upstream orifice assuring, when a leak occurs, a sufficient drop in pressure in the control chamber for the valving element to close.
Claim 10
Dependent Claim
35 words
The area ratio excess flow shutoff valve and system claimed in claim 7 wherein the valving element is disposed for translation between its open and closed position, and the passage is in the valving element.
Claim 11
Dependent Claim
66 words
The area ratio excess flow shutoff valve and system claimed in claim 8 wherein the valve has a body, the valving element being disposed in the body and having a head in the control chamber and a shank of smaller diameter than the head, the shank being in a bore of the body, the head having the control area and the shank having the source area.
Claim 12
Dependent Claim
74 words
The area ratio excess flow shutoff valve and system claimed in claim 9 wherein: first and second seal means is provided, respectively, between the wall of the control chamber and the head and between the wall of the bore and the shank to prevent fluid passing from the control and source chambers past the seal means, and a vent passage is provided in the body between atmosphere and the area between the seal means.
Claim 13
Dependent Claim
62 words
The area ratio excess flow valve claimed in claim 10 wherein when the valving element is in its open position the shank extends into the source chamber and the passage opens into the source chamber radially of the axis of the shank, and when the valving element is in its closed position the radial opening of the passage is in the bore.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |