| 主权项 |
1. A piston, comprising:
a piston housing having a central axis, a first end, a second end, a radially outer surface extending axially from the first end to the second end, and a radially inner surface extending from the first end to the second end; a decompression valve disposed in the piston housing, wherein the decompression valve includes a valve housing seated in the piston housing and a valve member moveably received by the valve housing, wherein the valve member has a radially outer surface including an annular shoulder; an end cap secured to the first end of the piston housing, wherein the end cap has a first end, a second end opposite the first end of the end cap, and a radially inner surface extending from the first end of the end cap to the second end of the end cap, wherein the radially inner surface of the end cap includes an annular valve seat; wherein the decompression valve has a closed position with the annular shoulder of the valve member engaging the valve seat of the end cap and an open position with the annular shoulder of the valve member axially spaced from the valve seat of the end cap; and a biasing member disposed within the valve housing and configured to bias the decompression valve to the closed position with the annular shoulder of the valve member in engagement with the valve seat of the end cap. |
