This single hinged expansion joint is designed for sulphur dioxide service in a sulphuric acid plant. It was fabricated with 321 stainless steel bellows and liner, and A-516 GR 70 carbon steel hinge plates and pipe. The pipe is 66" outside diameter and 35-1/4" overall length. The expansion joint was designed for 6° angular and 3 PSIG at 680°F. The bellows and pipe long seams were 100% x-rayed, and all the welds were 100% dye penetrant tested. A soap and air test at 15 PSIG was conducted prior to shipment.
Hinges permit angular rotation in one plane only by the use of a pair of pins through hinge plates attached to the expansion joint ends. Hinges and hinge pins are designed to restrain the thrust of the expansion joint due to internal pressure. Hinges can also be designed to carry piping loads, if specified.
Features of hinged expansion joints include:
- Angular rotation in one plane
- Eliminates pressure thrust forces
- Transmits external loads
- Prevents torsion on bellows
- No main anchors required
- Minimum guiding required
- Low forces on piping system
