The Expansion Joints Blog

The existing pressure balanced elbow expansion joint with liners was re-designed with turning vanes to eliminate the vibration impact on the bellows. U.S. Bellows performed a computational fluid dynamics (CFD) analysis to determine the design of the turning vanes.

Flow Path Comparison

The turning vanes redirect the flow stream, which creates a smoother flow, thus eliminating the flow induced vibration. The bellows and liner were fabricated from 321 stainless steel and the rest is fabricated from carbon steel. An air and soap test was performed prior to shipping it to a power plant in Washington.

8" Diameter Pressure Balanced Expansion Joints for a company in Ohio

U.S. Bellows, Inc. specially designed and fabricated two 770 lb. pressure balanced expansion joints for a company in Ohio. These expansion joints, designed for 450 PSIG and 1350 °F, will be used for wind tunnel testing of airplanes and engines. With an overall length of 70, these expansion joints consist of four 8 diameter bellows with 3 plies of Inco 625 Gr1 material, an 8 diameter Inco 800 HT elbow, four 74 A193 B8 tie rods, and four 2 thick A240 tp304H rings. To ensure quality, 100% x-ray and 100% dye-penetran tests were performed on the bellows. A pneumatic test at 550 PSIG was conducted on the entire assembly prior to shipping.