US Bellows custom-designed and manufactured an 18-inch diameter elbow pressure balanced expansion joint for a chemical processing plant used in the production of compound fertilizers. The expansion joint was engineered to accommodate thermal movement while minimizing pressure thrust loads in the piping system, making it well suited for the plant’s nitrogen oxide process.
The assembly measured 83-3/8 inches from the weld end to the centerline of the elbow. The body, pipe, covers, and tie rods were fabricated from 304L stainless steel, while the bellows and internal liners were manufactured from 321 stainless steel for enhanced high-temperature performance. The unit was designed to accommodate 1/2 inch of axial compression and 4-1/8 inches of lateral movement while operating at 600°F and 125 psig.
As part of PT&P’s quality assurance program, the completed assembly underwent 100% dye-penetrant examination and a hydrostatic pressure test at 190 psig prior to shipment to verify structural integrity and compliance with project specifications
