Pikotek® VCXT™ Isolating Gaskets/Kits


A serrated, machined metal core insulating gasket faced with high-temperature THERMa-PUR™, sleeves, washers, metal backing washers and a Garlock 5500 spacer ring.

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.


  • Fire safe in compliance with API 607 and API 6FB¹⁺²
  • THERMa-PUR™ is suitable for sealing across a wide range of chemicals (pH 0-14) and sweet and sour gaseous and liquid hydrocarbons ³
  • The standard 316L 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°F⁴
  • Better handling/shipping integrity than mica or vermiculite based products
  • Sizes available 1/2″ – 24″ NPS
  • Highest temperature rated isolating product available
  • Wide range of chemical resistance


  • 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)
  • Prevents 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.
  • A better option for steam applications than GRE


  • Operational pressure range: Full vacuum to ASME B16.5 1500# API
  • Maximum Operating Temperature Range: -328°F to 770°F (-200°C to 410°C)

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


Insulating Gasket & Washers

  • Core Thickness Facing Thickness: 3.2mm/.125” (316SS Core); 1mm/.040” (x2) (Facing)
  • Factor (m) ASME Minimum: 4.00
  • Seating Stress (y): 3625 psi (25 MPa)
  • Dielectric Strength (ASTM D149a): 3.937 kV/mm

Mica Insulating Sleeves

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