Claims
- 1. A valve comprising:
- a housing divided into a first chamber and a second chamber and having an inlet and an outlet defining a flow passage through said housing;
- a piston mounted in a bore in said flow passage and cooperating with said outlet to alter the flow area through said outlet;
- an orifice through said piston providing fluid flow from said inlet to said outlet;
- spring means biasing said piston toward said inlet, said spring means providing a bias force that establishes a substantially constant pressure differential between said first chamber and said second chamber to enable substantially constant outlet flow at varied pressures; and
- means having an alterable cross-sectional area encircling said orifice for altering fluid flow through said orifice.
- 2. The valve of claim 1 wherein said means for altering fluid flow is an inflatable bladder.
- 3. The valve of claim 2 wherein said inflatable bladder is ring-shaped.
- 4. The valve of claim 2 wherein said inflatable bladder is inflated and deflated by a pressurized fluid source.
- 5. The valve of claim 1 wherein said means for altering fluid flow is a deformable elastomer.
- 6. The valve of claim 5 wherein said deformable elastomer is ring-shaped.
- 7. The valve of claim 5 wherein said elastomer is deformed by a pressurized fluid source.
- 8. The valve of claim 5 wherein said elastomer is deformed by piston means.
- 9. The value of claim 1 wherein said means for altering fluid flow is a circumferentially variable ring.
- 10. The valve of claim 9 wherein said ring is unitary in construction.
- 11. The valve of claim 9 wherein said ring is split at one portion thereof.
- 12. The valve of claim 11 wherein said ring has one end secured to said valve.
- 13. The valve of claim 9 wherein the circumference of said ring is altered by piston means.
- 14. A valve comprising:
- a housing divided into a first chamber and a second chamber and having an inlet and an outlet defining a flow passage through said housing;
- a piston mounted in a bore in said flow passage and cooperating with said outlet to alter the flow area through said outlet;
- an orifice through said piston providing fluid flow from said inlet to said outlet;
- spring means biasing said piston toward said inlet, said spring means providing a bias force that establishes a substantially constant pressure differential between said first chamber and said second chamber to enable substantially constant outlet flow at varied pressures; and
- means for altering fluid flow through said orifice to adjust the fluid flow rate, said means for altering fluid flow comprising an inflatable bladder adjacent said orifice.
- 15. A valve comprising:
- a housing divided into a first chamber and a second chamber and having an inlet and an outlet defining a flow passage through said housing;
- a piston mounted in a bore in said flow passage and cooperating with said outlet to alter the flow area through said outlet;
- an orifice through said piston providing fluid flow from said inlet to said outlet;
- spring means biasing said piston toward said inlet, said spring means providing a bias force that establishes a substantially constant pressure differential between said first chamber and said second chamber to enable substantially constant outlet flow at varied pressures; and
- means for altering fluid flow through said orifice, said means for altering fluid flow comprising a deformable elastomer adjacent said orifice.
- 16. A valve comprising:
- a housing divided into a first chamber and a second chamber and having an inlet and an outlet defining a flow passage through said housing;
- a piston mounted in a bore in said flow passage and cooperating with said outlet to alter the flow area through said outlet;
- an orifice through said piston providing fluid flow from said inlet to said outlet;
- spring means biasing said piston toward said inlet, said spring means providing a bias force that establishes a substantially constant pressure differential between said first chamber and said second chamber to enable substantially constant outlet flow at varied pressures; and
- means for altering fluid flow through said orifice, said means for altering fluid flow comprising a circumferentially variable ring adjacent said orifice.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional of the prior application Ser. No. 08/224,477, filed Apr. 7, 1994, now U.S. Pat. No. 5,487,405, which is a continuation-in-part of U.S. patent application Ser. No. 08/069,459 filed Jun. 1, 1993, entitled "Flow Control Valve Having Adjustable Piston for Varying Flow Rate", to be issued Apr. 12, 1994 as U.S. Pat. No. 5,301,713.
US Referenced Citations (41)
Foreign Referenced Citations (3)
Number |
Date |
Country |
44-4950 |
Mar 1963 |
JPX |
772626 |
Feb 1978 |
ZAX |
1228079 |
Apr 1971 |
GBX |
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Entry |
"A Novel Approach to Flow Control for Chemical Injection and Continuous Sampling", M.S. Shelton, Society of Petroleum Engineers Publication Number 16910, pp. 329-338, Sep., 1987. |
"Automatic Flow Rate Controllers", Kates Company, a Taub Company, no date. |
"Primary Secondary Pumping Manual", ITT, no date. |
"Variable Speed/Variable Volume Pumping Fundamentals", ITT, no date. |
"A Chilling Story of the Bridge", BRDG-TNDR Corp. no date. |
"Design ED, EAD and EDR Control Valve Bodies", Fisher Corp. no date. |
"Flow Control", Westinghouse. no date. |
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Divisions (1)
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Number |
Date |
Country |
Parent |
224477 |
Apr 1994 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
69459 |
Jun 1993 |
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