Pressure relief valve devices and methods
Pressure relief valves for use in high pressure applications that may include a conical shaped plunger, a body with a conical shaped mating surface corresponding to the shape of the conical shaped plunger, and one or more sealing elements, such as a pair of O-rings, are disclosed.
1. A pressure relief valve for high pressure operation, comprising:
a plunger assembly including an elongate threaded shaft at a first end and a compliant cone-shaped sub-section with a smooth faced sealing surface at a second end opposite the first end;
a body for withstanding deep ocean external pressure of a depth of at least 1000 meters, the body including a cavity with a conical-shaped mating surface to receive the smooth-faced sealing surface of the plunger assembly, and a clip to restrain the plunger assembly at the second end;
a compression spring disposed between a portion of the plunger assembly and the body sized to withstand corresponding pressures of at depth of at least 1000 meters; and
one or more seals disposed between the body mating surface and the sealing surface of the plunger assembly; wherein the body mating surface and the sealing surface are held in contact by the compression spring.
2. The pressure relief valve of claim 1 , wherein the plunger assembly includes an adjustment element coupled to the cone shaped sub-section of the plunger to adjust an actuation pressure and an adjustment nut, and wherein the adjustment element includes a threaded shaft onto which the adjustment nut is screwed to adjust the cracking pressure of the valve by adjusting the compressing spring force, and wherein a flat face of the cone shaped sub-section is held substantially flush with the exterior of the body when external pressure is applied.
3. The pressure relief value of claim 1 , wherein the body includes an inner groove and an outer groove, and wherein the one or more seals comprise an inner O-ring and an outer O-ring correspondingly seated in the inner groove and the outer groove.
4. The pressure relief valve of claim 3 , wherein the inner O-ring and the outer O-ring have substantially the same cross-sectional diameter.
5. The pressure relief valve of claim 3 , wherein the inner O-ring and the outer O-ring have a different cross-sectional diameter.
6. The pressure relief valve of claim 3 , wherein the inner O-ring and the outer O-ring comprise the same material.
7. The pressure relief valve of claim 3 , wherein the inner O-ring and the outer O-ring comprise different materials.
8. The pressure relief valve of claim 3 , wherein the inner groove and the outer groove are oriented along an axis substantially perpendicular to a mating surface of the conical shaped cavity.
9. The pressure relief valve of claim 8 , wherein one or both of the inner groove and the outer groove have a rounded groove bottom.
10. The pressure relief valve of claim 8 , wherein one or both of the grooves include an undercut edge to prevent dislodging of O-rings during high flow rate discharges.
11. The pressure relief valve of claim 1 , wherein the cone shaped sub-section includes a thin compliant section configured to flex upon application of high applied pressures.
12. The pressure relief valve of claim 1 , further comprising a thread locking element to maintain a set point during operation.
13. The pressure relief valve of claim 1 , wherein the adjustment nut includes a plurality of anti-rotation fingers.
14. The pressure relief valve of claim 1 , further comprising a protective cap disposed on the valve to prevent access to a cracking pressure adjustment element of the valve.
15. The pressure relief valve of claim 1 , wherein the body includes a stop edge to prevent the compression spring from going beyond a predefined yield point.
16. The pressure relief valve of claim 15 , wherein the seal comprises a flat gasket.
17. A pressure relief valve for high pressure operation, comprising:
an adjustment nut;
a plunger assembly including a compliant cone-shaped sub-section with a sealing surface, an adjustment element coupled to the conical shaped sub-section of the plunger to adjust an actuation pressure, and an adjustment nut;
a body for withstanding deep ocean pressure, the body including a cavity with a conical-shaped mating surface to receive the sealing surface of the plunger assembly;
a compression spring disposed between a portion of the plunger assembly and the body; and
one or more seals disposed between the body mating surface and the sealing surface of the plunger assembly;
wherein the body mating surface and the sealing surface are held in contact by the compression spring, the length of the anti-rotation fingers is preset to provide a predefined cracking pressure when the adjustment nut is jammed against the plunger, and the adjustment element includes a threaded shaft onto which the adjustment nut is screwed to adjust the cracking pressure of the valve by adjusting the compressing spring force.
18. An underwater lighting device, comprising:
a deep sea pressure housing for a light or camera; and
a pressure relief valve screwed into a threaded hole in the housing, comprising:
a plunger assembly including an elongate threaded shaft at a first end and a cone-shaped sub-section with a smooth faced sealing surface at a second end opposite the first end;
a body for withstanding deep ocean pressure, the body including a cavity with a conical-shaped mating surface to receive the smooth-faced sealing surface of the plunger assembly, and a clip to restrain the plunger assembly at the second end;
a compression spring disposed between a portion of the plunger assembly and the body; and
one or more seals disposed between the body mating surface and the sealing surface of the plunger assembly; wherein the body mating surface and the sealing surface are held in contact by the compression spring.
19. A battery, comprising:
a battery housing; and
a pressure relief valve disposed in the battery housing to vent gases from within the housing, the pressure relief valve including:
a plunger assembly including an elongate threaded shaft at a first end and a cone-shaped sub-section with a smooth faced sealing surface at a second end opposite the first end;
a body for withstanding deep ocean pressure, the body including a cavity with a conical-shaped mating surface to receive the smooth-faced sealing surface of the plunger assembly, and a clip to restrain the plunger assembly at the second end;
a compression spring disposed between a portion of the plunger assembly and the body; and
one or more seals disposed between the body mating surface and the sealing surface of the plunger assembly; wherein the body mating surface and the sealing surface are held in contact by the compression spring.