Rupturable low pressure relief apparatus

A rupturable pressure relief apparatus which ruptures in either direction when a low pressure differential is exerted thereacross adapted to be sealingly clamped between inlet and outlet annular support members comprising:

• a first circular rupturable member formed of flexible material including a solid annular flange portion and a plurality of arcuate slots circumscribing a substantially circular central portion with rupture tabs between said arcuate slots;
• a second circular rupturable member formed of solid flexible material of a size corresponding with said first rupturable member positioned adjacent said first rupturable member;
• a third circular rupturable member positioned adjacent said second rupturable member on the opposite side thereof from said first rupturable member of a size corresponding with said first and second rupturable members, said third rupturable member being formed of flexible material and including a solid annular flange portion and a plurality of arcuate slots circumscribing a substantially circular central portion with rupture tabs between said arcuate slots;
• a first knife means having a cutting edge forming at least a portion of a circle positioned adjacent said first rupturable member on the side thereof opposite from the second rupturable member;
• a second knife means having a cutting edge forming at least a portion of a circle positioned adjacent said third rupturable member on the side thereof opposite from said second rupturable member whereby upon the rupture of either of the first or third rupturable members, the second rupturable member is cut by the cutting edge of the first or second knife means, respectively;
• and
• each of said first and third rupturable members including an annular metal protection ring attached to the side thereof facing said first or second knife means, said protection rings being sized such that when said first or third rupturable members flex into contact with the cutting edges of said first or second knife means, respectively, said protection rings prevent said rupturable members from being cut by said cutting edges but when said rupturable members rupture, said protection rings pass through said knife means.

A rupturable pressure relief apparatus which ruptures in one direction when a low pressure differential is exerted thereacross and which ruptures in the opposite direction when an opposite lower pressure differential is exerted thereacross adapted to be sealingly clamped between a pair of annular support members comprising:

• a first circular rupturable member having a plurality of radial slits formed therein extending from a solid central portion thereof to a solid annular flange portion thereof and having a plurality of openings formed therein between said slits and between said solid central portion and said solid annular flange portion;
• a second circular rupturable member positioned adjacent one side of said first circular rupturable member, said second rupturable member being formed of a solid flexible material and being of a size corresponding with said first rupturable member;
• a third circular rupturable member positioned adjacent said second rupturable member on the opposite side thereof from said first rupturable member of a size corresponding with said first and second rupturable members, said third rupturable member being formed of flexible material and including a solid annular flange portion and a plurality of arcuate slots circumscribing a substantially circular central portion with rupture tabs between said arcuate slots;
• knife means having a cutting edge forming at least a portion of a circle positioned adjacent said third rupturable member on the side thereof opposite from said second rupturable member;
• and
• an annular metal protection ring attached to the side of said third rupturable member facing said knife means, said protection ring being of a size such that when said third rupturable member flexes into contact with said cutting edge of said knife means, said protection ring prevents said third rupturable member from being cut by said cutting edge, but when said third rupturable member ruptures said protection ring passes through said knife means.

A rupturable pressure relief apparatus adapted to be clamped between the seating surfaces of a pair of conventional pipe flanges which ruptures in one direction when a low pressure differential is exerted thereacross and which ruptures in the opposite direction when an opposite lower pressure differential is exerted thereacross comprising:

• a first annular support member having a seating surface for sealingly coacting with the seating surface of one of said pipe flanges and having an oppositely facing annular seating surface;
• a first circular rupturable member having a solid annular flange portion for sealingly coacting with the annular seating surface of said first annular support member, having a plurality of radial slits formed therein extending from a solid central portion thereof to the solid annular flange portion thereof and having a plurality of openings formed therein between said slits and between said solid central portion and said solid annular flange portion;
• a second circular rupturable member positioned adjacent the side of said first rupturable member opposite from said first annular support member, said second rupturable member being formed of a solid flexible material and being of a size corresponding with said first rupturable member;
• a third circular rupturable member positioned adjacent said second rupturable member on the opposite side thereof from said first rupturable member of a size corresponding with said first and second rupturable members, said third rupturable member being formed of flexible material and including a solid annular flange portion for sealingly coacting with the peripheral portion of said second rupturable member and the annular flange portion of said first rupturable member and having a plurality of arcuate slots circumscribing a substantially circular central portion with rupture tabs between said arcuate slots;
• a second annular support member having an annular seating surface for sealingly coacting with the side of the annular flange portion of said third rupturable member opposite from said second rupturable member and having an oppositely facing seating surface for sealingly coacting with the seating surface of the other of said pipe flanges;
• knife means positioned adjacent said third rupturable member supported by said second annular support member having a cutting edge forming at least a portion of a circle;
• and
• an annular metal protection ring attached to the side of said third rupturable member facing said knife means, said protection ring being of a size such that when said third rupturable member flexes into contact with said cutting edge of said knife means, said protection ring prevents said third rupturable member from being cut by said cutting edge, but when said third rupturable member ruptures said protection ring passes through said knife means.