O-ring lubrication system

A pressure regulator comprising:

• a cylinder;
• a piston contained in the cylinder;
• first and second O-rings attached to the piston and configured to form a seal between the piston and an interior wall of the cylinder;
• an inlet;
• an outlet having a valve seat;
• a valve body attached to the piston;
• a biasing mechanism;
• and
• a lubrication system comprising:
• a lubrication reservoir between the first and second O-rings defined by an annular groove in an exterior surface of the piston and the interior wall of the cylinder, the annular groove defining first and second tapered ends of the reservoir that are displaced from each other along the central axis, the first tapered end tapering toward the interior wall with distance along the central axis toward the first O-ring, and the second tapered end tapering toward the interior wall with distance along the central axis toward the second O-ring;
• and
• an input port extending through the cylinder to the lubrication reservoir;
• wherein:
• the piston is configured to move along a central axis relative to the cylinder between first and second positions;
• the first and second O-rings are displaced from the input port during movement of the piston between the first and second positions;
• the biasing mechanism is configured to bias the piston toward the first position, in which the valve body engages the valve seat;
• and
• movement of the piston to the second position disengages the valve body from the valve seat.