Multi-fluid precision calibration pressure source
A pressure calibration device can include certain features that allow it to be used with a variety of hydraulic and pneumatic systems. A pressure calibration device can be configured to provide pressure or vacuum, and can have a mode selector for selecting to provide pressure or vacuum. A pressure calibration device can have a volume adjuster configured to modify pressures for hydraulic or pneumatic systems. A pressure calibration device can have a pressure release valve and a bleed valve for adjusting pressure values.
1. A portable calibration pressure device configured to generate vacuum and pressure, said calibration pressure device comprising:
a pump having an inlet and an outlet;
a manifold fluidly connected to the pump;
a reservoir fluidly connected to the pump; and
a selector valve configured for operation at pressures up at about 10,000 psi, the selector valve comprising:
a selector valve housing comprising a plurality of ports;
a spool positioned at least partially within the selector valve housing and configured to move axially within the selector valve housing from a first position to a second position, the spool comprising at least two recessed sections;
a plurality of spacer bushings positioned within the selector valve housing, wherein each port is adjacent a spacer bushing and the spacer bushings adjacent each port comprise at least one radial hole;
a plurality of sealing elements, at least one sealing element positioned between adjacent spacer bushings, the plurality of sealing elements configured to seal against an outer diameter of the spool;
a first fluid volume between a first recessed section of the spool and interior surfaces of the sealing elements and spacer bushings;
a second fluid volume between a second recessed section of the spool and interior surfaces of the sealing elements and spacer bushings; and
a cam unit configured to be grasped and rotated by a user, the cam unit comprising a notch that receives a pin that is rigidly connected with the spool, wherein the rotation of the cam unit moves the pin which in turn moves the spool within the selector valve housing;
the selector valve configured such that:
when the spool is in the first position, the reservoir fluidly communicates through one of the first and second fluid volume to the pump inlet and the manifold fluidly communicates through the other of the first and second fluid volume to the pump outlet, and
when the spool is in the second position, the reservoir fluidly communicates through one of the first and second fluid volume to the pump outlet and the manifold fluidly communicates through the other of the first and second fluid volume to the pump inlet.
2. The calibration pressure device of claim 1 , wherein the pump is a hand pump.
3. The calibration pressure device of claim 1 , wherein the spool is configured to have a third position between the first position and the second position such that when the spool is in the third position the reservoir fluidly communicates through one of the first and second fluid volume with the manifold.
4. The calibration pressure device of claim 1 , wherein rotating the cam unit causes the spool to move axially within the selector valve housing.
5. The calibration pressure device of claim 1 , wherein the cam unit comprises an angled slot configured to receive a pin that connects to the spool.
6. The calibration pressure device of claim 4 , wherein the cam unit rotates no more than 360 degrees to move the spool axially from the first position to the second position.
7. The calibration pressure device of claim 6 , wherein the cam unit rotates 120 degrees during movement of the spool axially from the first position to the second position.
8. The calibration pressure device of claim 1 , wherein the spacer bushings adjacent each port comprise at least one radial hole aligned with the port.
9. The calibration pressure device of claim 1 , wherein the plurality of sealing elements remain stationary relative to the selector valve housing when the spool moves from the first position to the second position.
10. The calibration pressure device of claim 1 , wherein a first port in the selector valve housing fluidly connects to the pump inlet and a second port in the selector valve housing fluidly connects to the pump outlet.
11. The calibration pressure device of claim 10 , wherein when the spool is in the first position, a third port is in fluid communication with the reservoir and is in fluid communication through the first fluid volume with the first port, and a fourth port is in fluid communication with the manifold and is in fluid communication through the second fluid volume with the second port.
12. The calibration pressure device of claim 11 , wherein when the spool is in the second position, a fifth port is in fluid communication with the reservoir and is in fluid communication through the second fluid volume with the second port, and the fourth port is in fluid communication with the manifold and is in fluid communication through the first fluid volume with the first port.
13. The calibration pressure device of claim 1 , wherein the cam unit further comprises a knob.
14. A portable calibration pressure device configured to generate vacuum and pressure, said calibration pressure device comprising:
a pump having an inlet and an outlet;
a manifold fluidly connected to the pump;
a reservoir fluidly connected to the pump; and
a selector valve configured for operation at pressures up at about 10,000 psi, the selector valve comprising:
a selector valve housing comprising a plurality of ports;
a spool positioned at least partially within the selector valve housing and configured to move axially within the selector valve housing from a first position to a second position, the spool comprising a first recessed section and a second recessed section;
the first recessed section comprising a first tapered portion, a second tapered portion, and an intermediate portion, the intermediate portion being located longitudinally between the first and second tapered portions, the intermediate portion comprising a generally constant diameter;
the first tapered portion and the intermediate portion each having a longitudinal length, the longitudinal length of the first tapered portion being greater than the longitudinal length of the intermediate portion;
a plurality of spacer bushings positioned within the selector valve housing, wherein each port is adjacent a spacer bushing and the spacer bushings adjacent each port comprise at least one radial hole;
a plurality of sealing elements, at least one sealing element positioned between adjacent spacer bushings, the plurality of sealing elements configured to seal against an outer diameter of the spool;
a first fluid volume between a first recessed section of the spool and interior surfaces of the sealing elements and spacer bushings;
a second fluid volume between a second recessed section of the spool and interior surfaces of the sealing elements and spacer bushings; and
a cam unit configured to be grasped and rotated by a user, the cam unit comprising a notch that receives a pin that is rigidly connected with the spool, wherein the rotation of the cam unit moves the pin which in turn moves the spool within the selector valve housing;
the selector valve configured such that:
when the spool is in the first position, the reservoir fluidly communicates through one of the first and second fluid volume to the pump inlet and the manifold fluidly communicates through the other of the first and second fluid volume to the pump outlet, and
when the spool is in the second position, the reservoir fluidly communicates through one of the first and second fluid volume to the pump outlet and the manifold fluidly communicates through the other of the first and second fluid volume to the pump inlet.
15. The calibration pressure device of claim 14 , wherein the second tapered portion has a longitudinal length that is greater than the longitudinal length of the intermediate portion.
16. The calibration pressure device of claim 15 , wherein the longitudinal length of the second tapered portion is about equal to the longitudinal length of the first tapered portion.
17. The calibration pressure device of claim 14 , wherein the cam unit comprises an angled slot configured to receive a pin that connects to the spool.
18. The calibration pressure device of claim 14 , wherein the cam unit rotates no more than 360 degrees to move the spool axially from the first position to the second position.
19. The calibration pressure device of claim 18 , wherein the cam unit rotates 120 degrees during movement of the spool axially from the first position to the second position.
20. The calibration pressure device of claim 14 , wherein the sealing elements comprise resilient O-rings with circular cross-sections.
21. The calibration pressure device of claim 14 , wherein the plurality of sealing elements remain stationary relative to the selector valve housing when the spool moves from the first position to the second position.
22. The calibration pressure device of claim 14 , wherein the taper of the first tapered portion is substantially constant.
23. The calibration pressure device of claim 14 , wherein the pump comprises a hand pump.
24. The calibration pressure device of claim 14 , wherein the spool is configured to have a third position between the first position and the second position such that when the spool is in the third position the reservoir fluidly communicates through one of the first and second fluid volume with the manifold.
25. A portable calibration pressure device configured to generate vacuum and pressure, said calibration pressure device comprising:
a pump having an inlet and an outlet;
a manifold fluidly connected to the pump;
a reservoir fluidly connected to the pump; and
a selector valve configured for operation at pressures up at about 10,000 psi, the selector valve comprising:
a selector valve housing comprising a plurality of ports;
a spool positioned at least partially within the selector valve housing and configured to move axially within the selector valve housing from a first position to a second position, the spool comprising a first recessed section and a second recessed section;
the first recessed section comprising a first tapered portion, a second tapered portion, and an intermediate portion, the intermediate portion being located longitudinally between the first and second tapered portions;
the first tapered portion tapering from a first diameter to a second diameter, the first diameter being greater than the second diameter;
the first tapered portion having a longitudinal length that is greater than the first diameter of the first tapered portion;
a plurality of spacer bushings positioned within the selector valve housing, wherein each port is adjacent a spacer bushing and the spacer bushings adjacent each port comprise at least one radial hole;
a plurality of sealing elements, at least one sealing element positioned between adjacent spacer bushings, the plurality of sealing elements configured to seal against an outer diameter of the spool;
a first fluid volume between a first recessed section of the spool and interior surfaces of the sealing elements and spacer bushings;
a second fluid volume between a second recessed section of the spool and interior surfaces of the sealing elements and spacer bushings; and
a cam unit configured to be grasped and rotated by a user, the cam unit comprising a notch that receives a pin that is rigidly connected with the spool, wherein the rotation of the cam unit moves the pin which in turn moves the spool within the selector valve housing;
the selector valve configured such that:
when the spool is in the first position, the reservoir fluidly communicates through one of the first and second fluid volume to the pump inlet and the manifold fluidly communicates through the other of the first and second fluid volume to the pump outlet, and
when the spool is in the second position, the reservoir fluidly communicates through one of the first and second fluid volume to the pump outlet and the manifold fluidly communicates through the other of the first and second fluid volume to the pump inlet.
26. The calibration pressure device of claim 25 , wherein the intermediate portion comprises a diameter that is less than the first diameter of the first tapered portion.
27. The calibration pressure device of claim 25 , wherein the intermediate portion comprises a diameter that is about equal to the second diameter of the first tapered portion.
28. The calibration pressure device of claim 25 , wherein the first tapered portion and the intermediate portion each have a longitudinal length, the longitudinal length of the first tapered portion being greater than the longitudinal length of the intermediate portion.
29. The calibration pressure device of claim 25 , wherein the cam unit comprises an angled slot configured to receive a pin that connects to the spool.
30. The calibration pressure device of claim 25 , wherein the cam unit rotates no more than 360 degrees to move the spool axially from the first position to the second position.
31. The calibration pressure device of claim 30 , wherein the cam unit rotates 120 degrees during movement of the spool axially from the first position to the second position.
32. The calibration pressure device of claim 25 , wherein the sealing elements comprise resilient O-rings with circular cross-sections.
33. The calibration pressure device of claim 25 , wherein the plurality of sealing elements remain stationary relative to the selector valve housing when the spool moves from the first position to the second position.
34. The calibration pressure device of claim 25 , wherein the pump comprises a hand pump.
35. The calibration pressure device of claim 25 , wherein the spool is configured to have a third position between the first position and the second position such that when the spool is in the third position the reservoir fluidly communicates through one of the first and second fluid volume with the manifold.