Pikotek® VCXT™ Isolating Gaskets/Kits

PTFE spring-energized primary sealing element and an E-ring secondary seal, seated in an insulating laminate and permanently bonded to a high-strength metal core, creating a fireproof gasket

The VCXT™ high temperature flange insulation sets create a seal and maintain electrical isolation across a wide range of seating stresses and flange classes in elevated temperature service. They can be used in load compromised connections; such as damaged and/or lined flanges and also heavily bolted connections where significant gasket stresses may be generated.

The insulating gaskets and washers have been designed and developed for use in standard pipeline flanges where both cathodic protection and high integrity sealing are required at elevated service temperatures. For non-standard bolted connections please consult your regional GPT sales manager.

Features and Benefits

  • Fire safe in compliance with API 607 and API 6FB
  • THERMa-PUR™ is suitable for sealing across a wide range of chemicals (pH 0-14) and sweet and sour gaseous and liquid hydrocarbons
  • Standard core and washer metallurgy are NACE (MRO175) compliant.
  • High compression characteristics achieve strong seal over wide range of flange surface finishes
  • Exceeds temperature capability of traditional vermiculite or glass/epoxy insulation sets - 770°F (410°C)
  • Better handling/shipping integrity than mica or vermiculite based products


  • Fire-safe flange insulation in conjunction with cathodic protection
  • Insulation between dissimilar metals to prevent galvanic corrosion
  • Wellhead isolation from inter-connected flow lines
  • Valve connections
  • Christmas Tree connections
  • Pump connections
  • Compressor connections
  • Mating mismatched ring-joint to raised-face flanges (VCFS will seal in ring-joint, raised-face and flat face/slip-on flanges)
  • Eliminate fluid trap corrosion between ring-joint (RTJ) flanges where high concentrations of CO2, H2S and other aggressive hydrocarbon media are present
  • Eliminate turbulence and flow-induced erosion between ring-joint (RTJ) flanges.



  • Operational pressure range: Full vacuum to ASME B16.5 2500lb
  • Operational temperature range: -328°F to 770°F (-200°C to 410°C)
  • Blowout Rating (650˚F): 4147 psi
  • Steam Test (hrs. performance @ 407˚F (208˚C)): 6285 hrs.
  • Electrical Test @ 500V DC: 35Gohms

Note: Electrical values are based on laboratory conditioned samples in laboratory conditions. Exposure to moisture or elevated temperature will change values.

Typical Physical Properties

Insulating Gasket & Washers

  • Core Thickness Facing Thickness: 4mm (316SS Core); 0.75mm (x2) (Facing)
  • Factor (m) ASME Minimum: 4.00
  • Seating Stress (y): 3625 psi (25 MPa)
  • Dielectric Strength (ASTM D149a): 9.8 kV/mm

Mica Insulating Sleeves

  • Maximum Temperature Dielectric Strength: +500˚C 20.0 kV/mm

Mica Washers

  • Stainless Steel: 0.125” thick

Other washer material can be provided to suit the application


The VCS Family of Electrical Isolation Gaskets

The VCS family is designed to withstand the Very Critical Service environments found in oil and gas, chemical and energy applications – providing uncompromising performance and safety.

Studs and nuts available upon request with all kitsStuds and nuts available upon request with all kits

Read 4032 times Last modified on Tuesday, 28 May 2019 18:12