Gasket Fitting Guide

We recommend the following best practices to ensure correct gasket fitting:

  • Care in material selection.
  • Care of flange faces.
  • Do not use jointing compounds.
  • Gasket sealant or not? (Generally no gasket sealant is required). See here for more information on gasket sealants.
  • Re-torque after 24 hours or one process cycle.


  • Choose as thin a material as possible.
  • Clean the flange faces and remove any dirt on the studs / bolts /nuts.
  • Lubricate the threads and the nut face. If possible use a lubricant based on:
  1. Molybdenum Disulphide
  2. Copper
  3. PTFE
  • Before assembly ensure that the nuts run freely on the threads.
  • Carefully fit the gasket taking care not to damage the gasket surface.
  • Tighten the bolts in the recommended sequence (eg diametrically opposite) to about half load.
  • Check visually that the flanges are uniformly loading the gasket.
  • Tighten to the recommended torque for the flange system.
  • After 24 hours of operation, or one process cycle, re-tighten to the correct torque (the gasket will have relaxed).
  • If the flange has not been in service and is unlikely to be so in the short term then still re-tighten.

Use of Graphic & other Anti-Stick Coatings:

  • Care should be taken to apply a very thin coating.
  • Not recommended where flanges are worn or where high pressures (in excess of 17 bar) are expected.
  • Do not use graphite grease.

    Our Commitment to Quality

    We pride ourselves on our commitment to quality and we are certified to:

    • BSI ISO 9001: 2015
    • BSI ISO 14001: 2015

    We hold the ADS SC21 Bronze Award certification for supplying into the defence and aerospace industries.