Systems and methods for piston check valves

A piston check valve system, comprising:

• a body;
• an upstream flange;
• a downstream flange, the downstream flange being disposed opposite the upstream flange;
• a piston secured within the body between the upstream flange and the downstream flange, the piston being moveable between a closed position in which an end face blocks a flow of fluid and an open position;
• and
• a cage surrounding a proximal end of the piston, the cage including a distal bridge configured to contact an outer periphery of the end face of the piston, the cage being configured to guide and retain the piston within the body.

A piston check valve, comprising:

• a body;
• an upstream opening;
• a downstream opening;
• a piston having a proximal end portion and a distal end portion, the piston being secured within the body between the upstream opening and the downstream opening and being movable between a closed position and an open position;
• a retainer contacting the proximal end portion of the piston;
• and
• a removable valve seat having an opening sized to receive the distal end portion of the piston when the piston is in the closed position, the opening of the removable valve seat formed by an inclined surface configured to form a seal with the distal end portion of the piston.