
US Bellows designed this thick-wall flanged and flued head expansion joint at a sulfuric acid plant in Louisiana. Sulfuric acid plants are located throughout the industrialized world, and we have worked with most of them, including market leaders. Most are located near their product acid’s point of use, i.e., near fertilizer plants, copper ore leach plants, and petroleum refineries. This is because elemental sulfur is cheaper to transport than sulfuric acid.
By far the largest amount of sulfuric acid is used to make phosphoric acid, which is, in turn, used to make the phosphate fertilizers, calcium dihydrogenphosphate, and ammonium phosphates. It is also used to make ammonium sulfate, which is a particularly important fertilizer in sulfur-deficient soils. In various concentrations, the acid is used in the manufacture of fertilizers, pigments, dyes, drugs, explosives, detergents, and inorganic salts and acids, as well as in petroleum refining and metallurgical processes.
The expansion joint was fabricated from A516-70 carbon steel and painted with a special epoxy coat for protection from corrosion. The unit is 96″ x 124-1/4″ O.D. All of the butt welds for this expansion joint were 100% liquid-penetrant, 100% radiographic, and soap and air bubble tested prior to shipment. This type of joint can be used as a “clamshell” joint in conjunction with shell and tube heat exchangers, steam exhaust, hot water return lines, or chilled water lines.
Read More






Externally pressurized pipe expansion joints, also known as X-Flex expansion joints, are suited for piping systems that require large amounts of axial compression or extension. In externally pressurized pipe expansion joints, the bellows elements are arranged so that the media flow is on the external surface of the bellows. Externally pressurizing the bellows eliminates pressure instability as a limitation to the design and permits the absorption of large amounts of axial expansion. Our QC department conducted various NDT examinations (X-Rays, PMI, Penetrant Tests, and Hydro Tests). Also provided were “weld maps” and MTR’s for client review and inspection. At U.S. Bellows, we are constantly developing and assisting client engineers in this effort toward decarbonation by designing innovative products to accommodate new and unusual design specifications.


