Flow control system for a valve
First Claim
1. A flow control system for a valve comprising:
- a valve body having a main flow passage connecting a first opening in communication with a first pressure area to a second opening in communication with a second pressure area;
a first valve with a shuttle piston having a first face in communication with the second pressure area through the main flow passage, a first seal at the first face which is operable to open and close the main flow passage, and a second face in communication with the second pressure area through a first orifice, the shuttle piston being biased to close the main flow passage and operable under differential pressure across the first and second faces to open the main flow passage;
a backpressure passage extending between the first opening and the shuttle piston'"'"'s second face; and
a second valve operable between opening and closing the second orifice wherein when the second orifice is closed, the shuttle piston is operable under differential pressure between the first and second pressure areas, and when the second orifice is open, the shuttle piston is operable under differential pressure between the second pressure area and the backpressure passage.
2 Assignments
0 Petitions
Accused Products
Abstract
A fluid-flow control system for a valve comprises a valve body and a bi directional main flow passage between a first and second fluid areas. The shuttle piston having a first face in direct communication with the second area and a second face in communication therewith through a bleed orifice. The second face is alternately exposed to the first fluid area through a backpressure passage and second orifice which alters the pressure differential across the shuttle piston. A second valve such as a solenoid operates to either close the second orifice wherein the shuttle piston is operable under differential pressure between the first and second pressure areas, or to close the second orifice wherein the shuttle piston is operable under differential pressure between the second pressure area and the backpressure passage. Filters at the fluid inlet and outlets protect the sealing components therein.
34 Citations
22 Claims
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1. A flow control system for a valve comprising:
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a valve body having a main flow passage connecting a first opening in communication with a first pressure area to a second opening in communication with a second pressure area;
a first valve with a shuttle piston having a first face in communication with the second pressure area through the main flow passage, a first seal at the first face which is operable to open and close the main flow passage, and a second face in communication with the second pressure area through a first orifice, the shuttle piston being biased to close the main flow passage and operable under differential pressure across the first and second faces to open the main flow passage;
a backpressure passage extending between the first opening and the shuttle piston'"'"'s second face; and
a second valve operable between opening and closing the second orifice wherein when the second orifice is closed, the shuttle piston is operable under differential pressure between the first and second pressure areas, and when the second orifice is open, the shuttle piston is operable under differential pressure between the second pressure area and the backpressure passage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification