SecureFlex Rubber Expansion Joints

The SecureFlex Van Stone interlocking flanges are compatible to mate with Lap-Joint Stub ends, Raised Face or Flat Full Face type flanges.  For other mating flange surfaces (wafer type check or butterfly valves), a full face hard spacer may be required. Consult UIP International, Inc. Engineering. The standard floating flanges are 150# drilled epoxy-coated carbon steel.  Galvanized, stainless steel and other alloy type materials are also available.  DIN-PN-JIS and other non-standard drill patterns customizable to your needs.

Kevlar® wrapped around a solid steel ring in the base of the rubber flange portion eliminates the tire cord from “pulling out” of the flange and provides superior sealing force when compressed against the mating flange during installation. The ring also prevents the distortion of the sealing surface if the installation tolerance is exceeded providing an “extra” margin of safety. Polyester tire cord may be substituted, with customer approval, for sizes 14” and above if design temperature does not exceed 250°F.

Our Flexible Tooling process allows us to manufacture the Expansion Joints to Non-Standard face-to-face dimensions. For smaller dimensions than Standard, design movements may be reduced.

Double and Triple arch expansion joints are also available for greater movement and reduced spring rates. We can also manufacture Concentric and Eccentric Tapers and Offset styles. Sizes up to 144” can be constructed.

Standard control rods that install out-board of the mating flanges are standard. Integral tie rods attached to the floating flanges can also be supplied.

NOTE: Decrease of working pressure for constructions made of Kevlar® above 350°F. Contact UIP International, Inc. Engineering for further details.

Bolt Torque Sequence

Finger-tighten all nuts and bolts. With a calibrated torque wrench, tighten each flange connection in a criss-cross pattern (refer to figure). Using this pattern, tighten in 20% increments up to 80% of the final bolt torque. To achieve the final torque value, tighten bolts in a sequential clockwise pattern once around the flange. Maximum recommended torque is suggested for systems that will be operating at or near the maximum pressure and temperature limits of the liner or conveying small molecular gasses.


Re-torquing after the initial installation, we recommend checking the torque of each bolt after 24 hours have elapsed or a temperature cycle or pressure cycle (hydrostatic test) has occurred. Any bolts falling below the recommended value should be retorqued. Values should only be exceeded by 10% increments when necessary to reseal. All torquing on the process system should be done when the system is ambient and cool.

Re-torquing should be performed annually, especially if the system experiences elevated temperatures or extreme temperature swings.

SecureFlex 7000 Available Materials and Temperature Ratings

  • PTFE/TFE/FEP-400°F
  • Viton® FKM/Fluoro-Elastomer-400°F
  • Chlorobutyl-250°F
  • EPDM-250°F
  • CSM-250°F
  • Neoprene-225°F
  • Nitrile-225°F
  • Natural Rubber-180°F
  • Gum Rubber-180°F

White FDA and NSF and Peroxide-Cured Elastomers also available. •300°F rating for EPDM and Chlorobutyl for air service at 50 psi max.