Cushioned Relief Valve

A fluid flow system comprising:

• at least one pipe;
• at least one check valve connected to the at least one pipe;
• and
• a cushioned relief valve connected to the at least one pipe downstream from the check valve,
• the cushioned relief valve including:
• a housing having an inlet, an interior, an outlet channel, and an outlet, the interior being a hollow cylinder with a first end in fluid communication with the inlet, a second end opposite the first end, and a cylindrical side between the first end and the second end, the cylindrical side in fluid communication with the outlet channel, the outlet channel extending from the cylindrical side of the hollow cylinder adjacent the first end to the outlet, the outlet opening outside the housing;
• a piston located within the hollow cylinder and slidable between a first position adjacent the first end of the hollow cylinder and a second position adjacent the second end of the hollow cylinder, the piston comprising a piston chamber inside the piston having an opening adjacent the first end of the hollow cylinder and a central aperture passing through an end of the piston opposite the opening, such that, when the piston is at the first position, the piston blocks the inlet and the outlet channel, and when the piston is in the second position, a path is opened for fluid flow between the inlet and the outlet channel;
• a cylinder cover defining a compressible gas volume in fluid communication with the second end of the hollow cylinder;
• and
• a flexible diaphragm separating the compressible gas volume of the cylinder cover from the second end of the hollow cylinder, the diaphragm being biased toward the first end of the hollow cylinder and defining a fluid volume in the hollow cylinder between the diaphragm and the end of the piston.

A cushioned relief valve, comprising:

• a hollow cylindrical body having a first open end, a second open end opposite the first open end and an outlet channel being in fluid communication with the first open end and extending through the hollow cylindrical body;
• a piston located within the hollow cylindrical body and slidable along an inner wall thereof between a first position adjacent the first open end of the hollow cylindrical body and a second position adjacent the second open end of the hollow cylindrical body, the piston comprising a first inner chamber exposed to the first open end of the hollow cylindrical body through an opening at a first end thereof and a central aperture passing through a second end thereof opposite the first end, in the first position the piston blocking the fluid communication between the first open end of the hollow cylindrical body and the outlet channel, and in the second position the piston opening the fluid communication between the first open end of the hollow cylindrical body and the outlet channel;
• a cylinder cover defining a second inner chamber in fluid communication with the second open end of the hollow cylindrical body;
• and
• a flexible diaphragm separating the second inner chamber from the second end of the hollow cylindrical body, the diaphragm being biased toward the piston and defining a third inner chamber in the hollow cylindrical body between the diaphragm and the piston.