Pressure relief device

A pressure relief device usable in a high-pressure fluid circuit for limiting the pressure in case of a failure of a circuit component comprising:

• a cylindrical body having a central bore, said cylindrical body having a stopped end toward a rearward end, said body having generally axially aligned lateral discharge openings axially spaced from a forward end of said body, a connective opening axially spaced from said discharge openings and wherein one of said discharge opening is connected with said connective opening;
• a valve seat piece closing off said body forward end, said valve seat piece having an upstream high pressure chamber, an orifice connected with a hemispheric seat arranged at an axially forward end of an axial well extending into said orifice, and said valve seat piece having a downstream chamber;
• a ball housed within said hemispheric seat for controlling fluid flow through said orifice;
• and
• a pusher devoid of an axial passage body mounted within said body central bore, said pusher having an axial protrusion for contacting said ball, and said pusher being biased by a compression spring within said bore to contact said ball to seal off said orifice, said pusher providing a pressure barrier dividing said central bore to a sealed control volume exposed to said connective opening and to another portion exposed to the valve piece downstream high pressure chamber, said pusher having a frontal face with a radial majority portion of said frontal face being perpendicular to said body central bore with a frontal face center portion connected with said protrusion, said frontal face majority portion partially throttling said discharge opening from an initial position with said ball contacting said orifice.