All-metal pressure relief valve

A method of manufacturing a pressure relief valve that forms a seal by mutual contact between rigid sealing surfaces, the method comprising:

• providing a seal plate having a fixed sealing surface and a mobile member having a mobile sealing surface;
• smoothing and flattening each of the sealing surfaces;
• and assembling the seal plate and mobile member into a housing such that:
• the mobile sealing surface is positioned in opposition to the fixed sealing surface, the mobile member being axially movable away from and toward the seal plate so as to alternately separate the sealing surfaces from each other and bring the sealing surfaces into direct contact with each other without use of an elastomer therebetween wherein the mobile member is a poppet that is maintained in axial alignment with the fixed sealing surface by a spacer having a flange with internal scalloped edges that establish and limit a maximum distance of separation between the sealing surfaces;
• the pressure relief valve is closed and prevents passage of a fluid from an inlet to an outlet when the sealing surfaces are in direct contact with each other without use of an elastomer therebetween, and the pressure relief valve is open and permits passage of the fluid from the inlet to the outlet when the sealing surfaces are separated from each other;
• and
• the pressure relief valve is configured to open when a pressure at the inlet is higher than a pressure at the outlet by more than a specified cracking pressure.

A pressure relief valve, comprising:

• a fluid inlet and a fluid outlet;
• a seal plate having a seal plate sealing surface, the seal plate being fixed in position within a housing;
• and
• a poppet having a mobile sealing surface positioned in opposition to the seal plate sealing surface, the poppet being axially movable away from and toward the seal plate so as to alternately separate the sealing surfaces from each other and bring the sealing surfaces into mutual contact with each other;
• wherein the mobile member is a poppet that is maintained in axial alignment with the fixed sealing surface by a spacer;
• wherein the spacer includes a flange having scalloped edges that establish and limit a maximum of distance separation between the sealing surfaces;
• wherein the pressure relief valve is closed and prevents passage of a fluid from the fluid inlet to the fluid outlet when the poppet and seal plate sealing surfaces are in direct contact with each other without use of an elastomer therebetween, and the pressure relief valve is open and permits passage of the fluid from the fluid inlet to the fluid outlet when the sealing surfaces are separated from each other;
• the pressure relief valve being configured to open when a pressure at the fluid inlet is higher than a pressure at the fluid outlet by more than a specified cracking pressure;
• wherein the poppet, seal plate, and the housing are all made from metal;
• and wherein the poppet includes a plurality of tabs that extend radially and slide along an inner surface of a surrounding surface so as to maintain the sealing surfaces in axial alignment with each other when the poppet moves toward and away from the seal plate, whereby the fluid is able to flow between the tabs when the pressure relief valve is open.