The Expansion Joints Blog

36" Pressure Balanced Elbow Expansion Joints

36" Pressure Balanced Elbow Expansion Joints

36" Pressure Balanced Elbow Expansion Joints

U.S. Bellows, Inc. designed and fabricated 36″ pressure balanced elbow expansion joints that weigh approximately 4,300 lbs each. The pressure balanced design does not exert pressure thrust on the equipment in the piping system.

36" Pressure Balanced Elbow Expansion Joints

The expansion joints are designed with Inconel® 625 grade LCF bellows and include a liner provided with drain holes to prevent accumulation of corrosive condensation. The design movements are 1/2″ axial compression and 3/4″ lateral movement. The bellows were 100% x-rayed before forming and dye-penetrant examined after forming.

44" Hinged Expansion Joints with Refractory Lining

U.S. Bellows, Inc. designed and fabricated two 44″ hinged expansion joints with 5″ thick refractory lining. These expansion joints are part of FCC stand-pipes in a synfuels plant. Each expansion joint is fabricated of two-ply Inconel® bellows and 3/4″ wall pipe. The joints consist of 2″ thick attachment rings. After fabrication, the expansion joints were pneumatically tested and inter-plies tested. The bellows and pipes were 100% x-rayed and PMI tested.

Refractory Lining

Thermal and structural Finite Element Analysis (FEA) was performed on the expansion joints to ensure the product is structurally sound and determining the thermal profile helps to prevent polythionic corrosion on the bellows. Design calculations were performed for all hardware including lug rings, gussets, hinge plates, pins, etc.