Patent ID: 7549678

Claim:
A system for actuating a pair of pipe flanges to cause the pipe flanges to sealingly engage, the system comprising: a first pipe flange having a first mating surface and a second pipe flange having a second mating surface complementary to the first mating surface; a coupling configured to engage the first and second flanges, wherein the coupling is rigidly connected to the second flange; a locking mechanism; and wherein when the coupling engages the first and second flanges, the first flange is oriented with the first mating surface toward the second mating surface of the second flange; wherein, when the coupling is engaged with the first flange, a cavity is formed between the coupling and the first flange; wherein, when fluid is forced into the cavity, fluid pressure within the cavity forces a first wall of the cavity, which is formed by the coupling, away from a second wall of the cavity, which is formed by the first flange, and thereby urges the first mating surface toward the second mating surface; and wherein the locking mechanism is configured to maintain sealing contact between the first and second mating surfaces after the fluid pressure forces the first and second mating surfaces into contact with each other, wherein the locking mechanism comprises a spacer positioned between the first flange and the coupling and wherein the spacer comprises a stepped ring configured to be placed in either: a first position in which steps of the spacer are within recesses in the first flange or coupling; or a second position in which steps of the spacer contact steps of the first flange or coupling.