Cryogenic pump with designed leakby for hydrogen fueling station

A hydrogen fueling station including a cryogenic pump, the cryogenic pump comprising:

• a first hydrogen pump cylinder;
• a first hydrogen piston at least partially positioned within the first hydrogen pump cylinder;
• at least one first seal extending about an upper portion of the first hydrogen piston and in sliding sealing engagement with the first hydrogen pump cylinder;
• a first coupler coupling a first end portion of the first hydrogen pump cylinder to a first end portion of a first thermal decoupling cylinder;
• a first blow by seal mounted to the first coupler and in sliding sealing engagement with the first hydrogen piston;
• and
• at least one relief valve in fluid communication with the first thermal decoupling cylinder,
• wherein
• a first variable volume working chamber is defined at least in part by the first hydrogen piston, the at least one first seal, and a second end portion of the first hydrogen pump cylinder opposite the first end portion of the first hydrogen pump cylinder,
• the at least one first seal is configured to provide leakage of hydrogen from the first variable volume working chamber past the at least one first seal to a first area between the first hydrogen piston and the first hydrogen pump cylinder on a side of the at least one first seal closest to the first coupler when a first hydrogen pressure is present in the first variable volume working chamber,
• the first blow by seal is configured to provide leakage of hydrogen from the first area past the first blow by seal into the first thermal decoupling cylinder when a second hydrogen pressure is present in the first area,
• the at least one relief valve is configured to provide leakage of hydrogen from the first thermal decoupling cylinder to maintain a third hydrogen pressure within the first thermal decoupling cylinder,
• the first hydrogen pressure is greater than the second hydrogen pressure, and
• the second hydrogen pressure is greater than the third hydrogen pressure.