These universal metallic expansion joints were custom designed for a pipe line in a bioengergy plant. They range from 20″ to 30″ in diameter, and are designed for 2″ lateral movement with a 1,362 lb/in. spring rate. The expansion joints are fabricated entirely from 304 stainless steel and designed for 250°F and 30 psig. Each unit was 100% dye penetrant examined and air tested prior to shipment.
This 118″ diameter tied universal expansion joint was designed for steam service in a power plant in Alaska. The expansion joint duct, tie rods and cover are fabricated from carbon steel with 304 stainless steel bellows and liner. The overall length is 225″. It was designed for 250°F at 7.25 PSIG and 3.52″ of lateral movement. Dye-penetrant testing, spot x-ray and an air and soap test were performed on the universal expansion joint assembly prior to shipping.
This tied universal expansion joint with control rods was designed for an oil recovery plant in Canada. It is 48″ in diameter and 68″ in overall length. This expansion joint was designed for 1″ compression, 4″ lateral and 15 psig at 150°F. The pipe was fabricated from A-36 carbon steel material and the bellows were fabricated from 316L stainless steel. A dye penetrant exam, air and soap test, along with a vacuum test was conducted prior to shipping.
A tied universal expansion joint was custom designed for service in an acid regeneration plant in Louisiana. It is 48″ in diameter, 141″ in overall length and designed for 1″ axial movement, 2-1/2″ lateral movement and .33° angular rotation. The expansion joint is fabricated with 310 stainless steel bellows, and 301 SS liner, duct, flanges, transition duct and covers. It was designed for 10 psig at 1150°F, and was dye penetrant examined, hydro-tested at 15 psig, and the bellows and pipe longitudinal weld seams were 100% x-rayed.
These universal metallic expansion joints were custom designed for an offshore application. They are 42″ diameter, 24″ overall length and designed for 2″ axial movement and 1-1/2″ lateral movement. The expansion joints are fabricated entirely from 316 L stainless steel and designed for 1,000°F and 1 psig. Each unit was 100% dye penetrant examined and soap and air tested prior to shipment.
These universal metallic expansion joints were custom designed for a chemical plant in Texas. They are fabricated entirely from stainless steel with 304 stainless steel bellows. The expansion joints are 12" diameter, 77-1/2" long and designed for 4-1/2" axial movement and 2" lateral movement. They were designed for 200°F and 100 psig. Each unit was 100% dye penetrant examined and hydrotested prior to shipment.
This week’s feature is on tied universal expansion joints designed for piping in a power generation plant in Texas. They are 6″ in diameter, 60″ in length, and will be used in a hot air application. The pipe, lugs and weld ends are fabricated from carbon steel, and the bellows are 321 stainless steel. The expansion joints are designed for 100°F at 3 psig and are capable of 6″ lateral movement. Each unit was 100% dye penetrant tested and soap and air tested prior to shipment.
This week’s featured product is on a hinged universal expansion joint and duct work assembly custom designed for an exhaust duct application in a power plant in Kenya. The hinge hardware was fabricated from carbon steel, while the rest of the unit was fabricated from 316 stainless steel with Inconel 625 bellows. An F-type variable spring was also provided for this project and will be used to support the center spool between the two elbows. The duct work with expansion joint is 36″ in diameter and the distance between the centerline of the two 90 degree elbows is 240″. It is designed for 20 psig at 115°F and 1/2 degree of angular movement. The entire assembly was 100% dye penetrant tested and a soap and air test was performed prior to shipment.
The universal expansion joint consists of two bellows separated by a pipe section or spool. The primary purpose of this arrangement is to have a unit which will accept large amounts of lateral deflection. The amount of lateral deflection they can accept is a function of the amount of angulation each bellows can absorb and the distance between the bellows. For a given bellows element, the amount of lateral deflection capability can be increased or decreased by simply changing the length of the center spool. In our Expansion Joint Catalog, three standard overall lengths are given with their lateral movement capability. If the piping problem requires greater capability, then the overall length can be increased to suit.
Since deflections are the result of piping thermal expansion, and universal expansion joints are usually long, our units are designed so that the thermal expansion within the tie rods is absorbed as axial compression by the two bellows elements. In this way, the overall length of the unit does not change when the piping is in service. The standard units in our Expansion Joint Catalog have all been designed to accept the thermal expansion of their length within the tie rods when the temperature is up to the design temperature shown.
You can view some of our past universal expansion joints on our blog.
Universal expansion joints are usually supplied with tie rods. Tie rods connect the ends of the unit to each other and restrain the pressure thrust load. This unit cannot accept any externally applied axial deflections. The thermal expansion of the distance between the tie rods —within the expansion joint— will be taken by the bellows element, as described above. The tie rods usually come in sets of two or more, equally distributed around the circumference of the expansion joint. When only two are provided, 180 degrees apart, the expansion joint is free to bend, or deflect angularly, as well as laterally. With three or more tie rods, since rods are loaded equally by the pressure thrust, only lateral deflections are possible without significant forces being applied by the adjacent piping.
See more pictures of universal expansion joints in our photo gallery.
U.S. Bellows designed and fabricated a 180″ long double gimbal expansion joint with a 90° elbow and flanged and flued head bellows, and a 114″ long single hinged expansion joint with flanged and flued head bellows. After performing a pipe stress analysis on the line, it was determined that spring supports were necessary, so F-Type variable spring supports were also provided for this project and shipped with the expansion joints.
All material in contact with the service fluid is fabricated from 304 H stainless steel and all external hardware is 304 stainless steel. The expansion joint bellows is designed for 5° angular movement and 1100°F at 10 psig. A spot x-ray test, soap and air test, and 100% dye penetrant examination on all welds were performed prior to shipment.
