Patent ID: 6805155
Filing Date: 2004-10-19
Classification: F16K,Y10T

Abstract:
A relief valve comprising:a cage having an axial bore; a moveable member disposed within the axial bore of the cage, the moveable member comprising a first end and a second end, the moveable member having an axial bore extending from the first end to the second end; a fixed member disposed within the axial bore of the cage adjacent to the second end of the moveable member, a chamber being defined between the moveable member and the fixed member; a piston disposed within the axial bore of the moveable member and at least partially extending into the chamber, the piston comprising a stem having a slotted section and a non-slotted section, the piston having at least a first position, in which the non-slotted section is outside of the axial bore of the movable member at its first end, and a second position, in which the non-slotted section is at least partially inside the axial bore, wherein, when the piston is in the first position, the relief valve is capable of passing fluid through the axial bore of the movable member, around the slotted section of the piston, and through the chamber, and wherein, in response to a decrease in pressure in the chamber, the piston moves toward the fixed member from the first position to the second position, thereby restricting the flow of the fluid through the axial bore.