Subsea hydraulic pressure boosting and regulating system
A hydraulic boosting and regulating system includes an intensifier circuit and a regulator and employs low leak, low crossover valves.
1. A system comprising:
at least one hydraulic intensifier circuit accepting a supply pressure and returning a boosted pressure that is higher than the supply pressure;
at least one regulator that accepts the boosted pressure and returns a regulated lower, regulated pressure that is lower than the boosted pressure;
a reciprocating piston having a first side and an opposed second side, each of the first and second side having with a larger low-pressure region and a smaller high pressure region;
a first three-way control valve selecting for supply pressure or vent to the first side low pressure region of the reciprocating piston; and
a second three-way control valve selecting for supply pressure or vent to the second side low pressure region of the reciprocating piston;
wherein a low pressure applied to the first side low pressure region moves the piston to create a high pressure on the second side high pressure region; and
wherein the low pressure applied to the second side low pressure region moves the piston to create the high pressure on the first side high pressure region.
2. The system of claim 1 , wherein
the first three-way control valve provides supply pressure to the first side low pressure region when not piloted and vent to the first side low pressure region when piloted; and
the second three-way control valve provides supply pressure to the second side low pressure region when not piloted and vent to the second side low pressure region when piloted.
3. The system of claim 1 wherein the second control valve pilots the first control valve.
4. The system of claim 3 , wherein the piston, when making a first movement toward the second side closes a first two-way valve thereby blocking vent to a pilot port of the second control valve.
5. The system of claim 4 , wherein the piston, when making a second further movement toward the second side opens a second two-way valve thereby providing supply pressure to the pilot port of the second control valve.
6. The system of claim 5 , wherein the piston, when making a first movement toward the first side closes a third two-way valve thereby blocking supply pressure from the pilot port of the first control valve.
7. The system of claim 6 , wherein the piston, when making a second further movement toward the first side closes a fourth two-way valve thereby providing vent to the pilot port of the second control valve.
8. The system of claim 7 , wherein the first and third two-way valves are normally open.
9. The system of claim 8 , wherein the second and fourth two-way valves are normally closed.
10. The system of claim 9 , wherein the second and fourth two-way valves remain piloted by supply pressure once piloted by contact with the piston.
11. The system of claim 10 , wherein additional return bias is provided to the second one-way valve by the first control valve when supply pressure is provided to the first side low pressure region, and additional return bias is provided to the fourth one-way valve by the second control valve when supply pressure is provided to the second low side pressure region.
12. The system of claim 1 , wherein at least the first three-way control valve further comprises:
casing defining a pilot port, a first operating port, a second operating port, and a third operating port;
a lower spool configured to displace against a first spring bias in response to pressure at the pilot port;
an upper spool defining an upper spool port in fluid communication with the third operating port and a lower spool port in fluid communication with the second operating port, the upper spool slidingly receiving the lower spool and displacing against a second spring bias in response to pressure from the lower spool, and having a hollow interior allowing fluid communication between the upper spool port and lower spool port when not under pressure from the lower spool such that the third and second operating ports are in fluid communication; and
a seat insert slidingly engaged with the lower spool on a lower region thereof, the lower region of the lower spool blocking fluid communication with the first operating port when seated against the seat insert;
wherein the lower spool is configured to engage against the upper spool upon a first displacement of the lower spool blocking the lower port of the upper spool and thereby blocking fluid communication between the third and the second operating ports;
wherein a second further displacement of the lower spool moves an inletted portion of the lower region into the seat insert allowing fluid communication between the second and first operating ports.
13. The system of claim 12 , wherein the lower region of the lower spool further comprises a non-inletted portion that blocks fluid communication through the seat insert to the first operating port during at least a portion of the first displacement.
14. The system of claim 1 , wherein the regulator further comprises:
a pilot stage comprising:
a pilot housing;
an upper member in the housing biased toward a middle member in the housing;
the middle member seating against the upper member and providing main pilot port pressure against the upper member and further seating against the pilot housing to selectively block supply pressure from a lower member;
the lower member fixed to the pilot housing and providing a spring biasing the middle member against the upper member;
wherein the upper member displaces the middle member to allow pressure into the lower member and pilot port when the bias of the upper member exceeds the spring bias combined with a pressure in the main pilot port;
wherein the middle member displaces the upper member to seat on the housing and stops supply pressure into the main pilot port when the spring bias and pressure in the main pilot port exceeds the bias of the upper member; and
wherein pressure from the main pilot port can separate the upper member from middle member and allow fluid to flow through the lower member, middle member, and upper member to vent via a passage in the pilot housing.
15. The system of claim 14 , wherein the regulator further comprises:
a main stage piloted by the main pilot port pressure to displace a valve from an internal valve seat and allow flow from a supply port to a regulated port.
16. The system of claim 15 , wherein the regulator further comprises:
a spool interposing the valve and the pilot port to receive pressure from the pilot port and displace the valve from the valve seat against a spring;
wherein the spool is hollow admitting regulated pressure internally and further has an internal spring biased cup selectively venting the regulated port pressure when regulated port exceeds a predetermined limit.
17. A pressure intensifier circuit comprising:
a reciprocating piston having a first side and an opposed second side, each of the first and second side having with a larger low-pressure region and a smaller high-pressure region;
a valve arrangement configured to shift application of supply pressure from the first side low pressure region to the second side low pressure region and vice versa in response to actuation by movement of the piston;
wherein the supply pressure applied to the first side low pressure region moves the piston to create a high pressure on the second side high pressure region;
wherein the supply pressure applied to the second side low pressure region moves the piston to create the high pressure on the first side high pressure region; and
wherein the valve arrangement further comprises:
a first three-way control valve selecting for supply pressure or vent to the first side low pressure region of the reciprocating piston; and
a second three-way control valve selecting for supply pressure or vent to the second side low pressure region of the reciprocating piston;
wherein the first three-way control valve provides supply pressure to the first side low pressure region when not piloted and vent to the first side low pressure region when piloted; and
wherein the second three-way control valve provides supply pressure to the second side low pressure region when not piloted and vent to the second side low pressure region when piloted.
18. The intensifier circuit of claim 17 wherein:
the second control valve pilots the first control valve;
the piston, when making a first movement toward the second side closes a first two-way valve thereby blocking vent to a pilot port of the second control valve;
the piston, when making a second further movement toward the second side opens a second two-way valve thereby providing supply pressure to the pilot port of the second control valve;
the piston, when making a first movement toward the first side closes a third two-way valve thereby blocking supply pressure from the pilot port of the first control valve; and
the piston, when making a second further movement toward the first side closes a fourth two-way valve thereby providing vent to the pilot port of the second control valve.
19. A regulator circuit comprising:
a pilot stage comprising:
a pilot housing;
an upper member in the housing biased toward a middle member in the housing;
the middle member seating against the upper member and providing main pilot port pressure against the upper member and further seating against the pilot housing to selectively block supply pressure from a lower member;
the lower member fixed to the pilot housing and providing a spring biasing the middle member against the upper member;
wherein the upper member displaces the middle member to allow pressure into the lower member and pilot port when the bias of the upper member exceeds the spring bias combined with a pressure in the main pilot port;
wherein the middle member displaces the upper member to seat on the housing and stops supply pressure into the main pilot port when the spring bias and pressure in the main pilot port exceeds the bias of the upper member; and
wherein pressure from the main pilot port can separate the upper member from middle member and allow fluid to flow through the lower member, middle member, and upper member to vent via a passage in the pilot housing;
a main stage piloted by the main pilot port pressure to displace a valve from an internal valve seat and allow flow from a supply port to a regulated port; and
a spool interposing the valve and the pilot port to receive pressure from the pilot port and displace the valve from the valve seat against a spring;
wherein the spool is hollow admitting regulated pressure internally and further has an internal spring biased cup selectively venting the regulated port pressure when regulated port exceeds a predetermined limit.