U.S. Bellows custom designed tied universal expansion joints with 304 stainless steel bellows from 2″ to 18″ diameter for a chemical plant in Texas. The expansion joints are designed for 3″ lateral movement at 122°F and 100 psig. The expansion joints were hydro-tested at 150 psig and delivered in six weeks.
U.S. Bellows refurbished a 54″ dia. custom crossover expansion joint for a power plant in Kansas. The flow end and balancing end bellows were replaced. The pressure balanced expansion joint was designed for 1″ axial movement at 700°F and 150 psig. The bellows longitudinal weld seams were 100% x-rayed and the assembly was hydro-tested at 180 psig prior to shipment. The refurbishment was completed in three weeks to meet the customer’s outage requirements.
Splicing of fabric expansion joints is a critical operation which needs to be performed correctly for the expansion joint splice to hold up under system operating conditions. ensureAsplice is the answer to assure that a splice is made correctly.
U.S. Bellows material is a thin, flexible, lightweight, PTFE material that clearly indicates when the proper conditions have been established for achieving a successful test splice on FLEXXCEL Fabric Expansion Joint materials. The U.S. Bellows material accomplishes this in two ways. First, a dramatic color change in the product during the splicing procedure ensures that the critical sealing temperature has been reached in the splice area. In addition, the material bonds to the expansion joint’s PTFE surface, confirming that sufficient pressure was applied during the splicing operation.
The sealing process requires that all splice components be assembled between the heat sealer and the product. As the splice heats up, the U.S. Bellows product changes from a light shade of red to a much darker shade of the red. The easily observed color change can only take place after the splice components have reached the critical sealing temperature required for PTFE products. If sufficient pressure has been applied as the color change occurs, the product will adhere to the expansion joint’s PTFE surface, confirming that the proper splicing conditions were achieved.
A successfully completed test splice utilizing the ensureAsplice material will ensure that the variables that exist during a field splice have been accounted for. The actual splice on the expansion joint can now be completed with confidence.
Variables to consider:
- Ambient conditions
- Length of extension cord
- Acceptable voltage
- Proper “backer board” usage
- Heat Seal Iron in good working condition
- Allow iron time to reach required temperature
- Be sure the green light is illuminated
- Proper amount of time used to splice
- Proper amount of pressure applied during splice
- Follow U.S. Bellows splice procedures
Shown are the items required to produce a test splice with the product
(Heat seal iron, backer board, FLEXXCEL belting material, PFA heat sealing film, ensureAsplice product, stapler, scissors, blade knife, tape measurer, marking pen)
2. Begin by placing the product on the “Backer Board” surface.
3. Overlap the 2 pieces of FLEXXCEL belt material. The overlap should be the same width as the PFA Film. Make sure the PFA film is residing between the two belt ends in the overlap splice area. Staple the PFA Film in place.
View the full instructions at: http://www.usbellows.com/fabric-catalog/ensureasplice.html
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.