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.
This universal rectangular expansion joint is fabricated entirely of carbon steel with COR-TEN™ steel bellows for a mining operation in the mountains of Chile. COR-TEN™ steel is high strength and ideal for resisting corrosion. It measures 73-1/4″ L x 52″ W x 96″ H, weighs 2,700 lb. and was painted with universal shop primer. This expansion joint was 100% dye penetrant tested, and a soap and air test was performed prior to shipment.
This universal flanged and flued head expansion joint and duct work assembly is designed for a 90″ diameter line. It includes slotted hinge plates installed across the bellows to carry the weight of the duct between the bellows and equalize the axial compression between the two bellows. The flanged and flued heads, duct and weld ends are fabricated from 304 H stainless steel. The expansion joint is designed for 2″ axial compression, 2-1/2″ lateral deflection, and 1150°F at 5 PSIG. A spot x-ray test, soap and air test, and 100% dye penetrant exam were performed prior to shipment.
This universal expansion joint is designed with 5″ thick refractory-lining for a 52″ pipe in a Styrene Plant in Thailand. It measures 154″ long and is fabricated with ASTMA 304H stainless steel pipe ends and Incoloy 800H bellows. The expansion joint is designed for a lateral movement of 6.982″ with a design pressure of 30 psig at 1085°F. The bellows and pipe longitudinal seams and the pipe circumferential welds were x-rayed. All welds were also dye penetrant examined. A pneumatic test between the plies at 15 psig and the complete expansion joint at 45 psig was performed. The carbon steel surfaces were coated with a special three-coat paint system after testing and prior to shipment.
U.S. Bellows offers all types of metallic expansion joints. Each type has advantages and limitations that can provide flexibility, load reduction, structural integrity and reliability required in a piping system.
Metal expansion joints can withstand the design temperatures and pressures, as well as provide the capacity necessary to absorb thermal growth of the piping system. The thermal movement required can be axial, lateral or angular. In some cases, the pressure thrust of an expansion joint must be restrained by the use of tie rods, hinges or a gimbal while allowing the bellows to move through its design deflections.
Learn more about the different types of metallic expansion joints:
Single Expansion Joints —— Universal Expansion Joints ——- Hinged Expansion Joints
Categories: Metallic Expansion Joints Dresser® Style, Externally Pressurized Expansion Joints, Flanged & Flued Head Expansion Joint, Gimbal Expansion Joints, Hinged Expansion Joints, In-line Pressure Balanced Expansion Joint, Pressure Balanced Elbow Expansion Joints, Rectangular Metallic Expansion Joints, Single Expansion Joints, Slip-type Expansion Joints, Thick-wall Expansion Joint, Toroidal Bellow Expansion Joint, Universal Expansion Joints
48″ Universal Expansion Joints
PT&P designed and fabricated 48″ universal expansion joints for a refinery. The bellows and flow liner are 316 stainless steel, while the rest of the expansion joint is carbon steel. These expansion joints are capable of 5.3″ axial compression, 2.0″ lateral, and 5° of angular movement. They are designed to operate at 25 PSIG with temperatures up to 150°F. A hydro-test and X-ray test was performed prior to shipment.
50 Universal Expansion Joints for an Air Force Base in New Mexico
U.S. Bellows, Inc. fabricated 50 expansion joints from 304L stainless steel. The expansion joints were 6″ and 8″ sizes. The 6″ expansion joints are 24″ face-to-face and the 8″ expansion joints are 26″ face-to-face. All of the expansion joints are fabricated with liners that are also made with 304L stainless steel. The design temperature was 200°F and the design pressure was 200 PSIG. The expansion joints were dye-penetrant tested and hydro-tested at 300 PSIG. U.S. Bellows, Inc. provides 100% customer satisfaction in terms of quality and delivery.
Expansion Joints for an Epoxy Resin Plant in Saudi Arabia
U.S. Bellows, Inc. designed and fabricated a 32″ universal expansion joint and 3″ single expansion joints to be utilized in a new epoxy resin plant in Saudi Arabia. The expansion joints are fabricated with stainless steel bellows and carbon and stainless steel flanges. The 32″ expansion joint has a design temperature of 482ºF with a design pressure of 15 PSIG. The 3″ single expansion joints have a design temperature of 400ºF with a design pressure of 370 PSIG.
The flanges on the 32″ universal expansion joint were custom fabricated to the customer’s special design requirements. One end of the 32″ expansion joint has a stainless steel custom machined flange with a grooved facing. The other end has a carbon steel lap joint flange. Each expansion joint was 100% dye-penetrant tested as well as hydro-tested.
Universal Expansion Joints for an Engineering and Construction Company
Universal Expansion Joints for an Engineering and Construction Company
These pictures display one of many tied universal expansion joints in a large order of expansion joints designed by U.S. Bellows, Inc. for a local engineering and construction company. These expansion joints weigh 1,600 lbs. each and are 10 inches in diameter. They are designed for 611 PSIG and temperatures up to 180°F. These expansion joints are fabricated from 321 carbon steel pipe, tie rods and 300 lb. RF weld neck flanges. The bellows longitudinal seams were 100% x-rayed and the complete assembly was hydro-tested to 917 PSIG to ensure a quality product and performance. The units were shipped with the mating flanges bolted to the end of the assembly.