Form-in-Place Sealex® Joint Sealant

Sealex®Sealex® joint sealant, specially processed, 100% pure PTFE on a roll, provides soft, highly compressible gasketing for longer life and trouble-free sealing. Its form-in-place versatility also cuts maintenance and storage costs. The high compressibility of Sealex® enables it to effectively fill flange imperfections for a tight, leak-free seal. Under pressure, it provides a very wide, thin ribbon-like joint sealant. Unlike conventional PTFE which is prone to cold flow, Sealex® has good creep resistance and bolt torque retention properties.

Sealex® joint sealant does not support bacterial growth or cause product contamination and is FDA compliant. It has virtually no shelf-life concerns since PTFE is unaffected by normal environmental conditions.

It has excellent resistance properties to chemical attack. It is ideal for most chemical services at temperatures to 500°F (260°C) and pressure to 2,000 psi (138 bar). It is also suitable for cryogenic use to -321°F (-196°C).

The joint sealant is available in roll form which helps reduce storage space, and is available in a wide variety of thicknesses and lengths.

Sealex® Installation Instructions

Sealex®Just follow the simple installation instructions. Select the size Sealex®. Use a size with nominal width of between 1/3 and 1/2 of the effective flange sealing width.

  1. Make sure that the sealing flanges are clean.
  2. Cut off a length of Sealex® just a little longer than the actual circumference of the perimeter of the seal.
  3. Peel off the adhesive protection strip, and press the Sealex® into position. Cross the free ends of the joint sealant adjacent to the bolt hole.
  4. Bolt up the mating surfaces using the recommended clamping force and bolt tightening patterns.


  • Fume ducts
  • Concrete lids
  • Glass joints
  • Heat exchangers
  • Fiberglass reinforced plastic vessels
  • Pump or compressor housing flanges
  • Steam vessel flanges
  • Ceramic joints
  • Water systems
  • Valves and piping

Gallagher Fluid Seals is a distributor of Thermoseal®, An Independent KLINGER Company, and stocks various widths and thicknesses of Sealex® Joint Sealant.  Contact us if you have questions about implementing Sealex® into your processes.