Profile: Precision Bellows Mfg. manufactures a wide variety of custom designed expansion joint assemblies. Our product includes single unrestrained, dual unrestrained, single bellows, rectangular bellows and externally pressurized. Our single unrestrained are used to absorb thermal expansion or contraction in piping systems, engine and heat exchangers. Dual unrestrained are used as a flex connections on diesel engines, pump connectors and gas tubines. Single bellows offers a wide range of bellows elements in sizes ranging from 1.0 inch diameter to 16.0 feet diameter in all materials.