The Expansion Joints Blog

Externally Pressurized Expansion Joints

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These 15 pressure relief safety valve connector expansion joints were manufactured from 316SS, A-335 P22, A-387 Gr22, A106, and A-51670. They were externally pressurized to prevent steam blow back. These externally pressurized expansion joints were attached to the relief valves in the power plant. They assist in maintaining pressure as well as provide for 7 axial and 6 lateral travel. These joints can handle applicable loads of up to 150 PSIG at 535F and 460 PSIG at 885F, but can function if temperatures reach 1,000F. They range from 30 to 85 in length and weigh between 400 lbs and 1,600 lbs. Dye penetrate, air, and soap bubble tests were completed for quality and performance assurance.