1300 098 060

Flange Isolation Kits

Flange Isolation Kits (or FIK as they are sometimes known) are designed to maintain the integrity and reliability of a piping system. Available for all flange sizes, types, pressure rating and materials, the kits provide an effective seal and electrically isolate each flange. By eliminating metal-to-metal contact, static current is halted to prevent corrosion and aid in the cathodic protection of the pipe.

Flange Isolation Kits are also utilised to isolate the mating surfaces of two dissimilar joining flanges (e.g. 316 SS to a Carbon Steel flange on a tank). This is mainly for the prevention of galvanic corrosion. The use of FIKs in such situations eliminates the electrochemical reaction which takes place when dissimilar metal flanges come into contact with the process fluid.

AG offers our Flange Isolation Kits in a range of different combinations to suit various flange types, pressure ratings and operating conditions. The information below provides an overview of available types with more information on each, or assistance in selecting the best combination of options for your application, available from your local AG branch.

Standard Kit Options

Single Washer Flange Isolation Kit

A single washer flange isolation kit is made up of a single isolating and sealing gasket to suit the flange size specified (Full Face is the usual option though ring face gaskets are also available) along with Insulating Bolt Sleeves (1 per bolt) and both insulating and steel washers (1 of each per bolt). Materials for each can be varied to suit individual application conditions.

Double Washer Flange Isolation Kit

A double washer FIK is made up of a sealing and isolating gasket to suit the flange size specified (again, full face and ring are available) as well as Insulating Bolt Sleeves (1 per bolt) and both insulating and steel washers (2 of each per bolt). Materials for each component can be varied to match application requirements.

One Piece Sleeve and Washer Flange Isolation Kit

Our one-piece sleeve and washer kits are made up of a sealing and isolating gasket, steel washers (two per bolt) and a one piece bolt sleeve and isolating washer (1 per bolt, manufactured to suit the dimensional requirements of the bolts used). These kits are easy to install and can have the materials for each individual component adjusted to match applications requirements.

Available Material Options

Isolating and Sealing Gaskets

The gaskets supplied with AG’s FIKs can be manufactured out of a wide range of materials to match the needs of a range of applications. Each of these are available in either full face (designed to fit to the outside of the flange with holes for the bolts) or ring face (sit inside the bolts whilst extending to the ID of the flange) styles. The most common materials are listed below:

  • Rubber Faced Phenolic Gaskets
  • PTFE Gaskets
  • Phenolic Fabric Reinforced Laminate Gaskets
  • Epoxy Glass Gaskets
  • GasketSeal® Sealing Gaskets (Consists of two moulded semi “O” rings mounted in grooves on opposite sides of an isolating retainer. These gaskets are self energising and allow the a seal to be created with low bolt loads)
  • LineBacker® Sealing Gaskets (A high quality gasket made from with a rectangular rubber sealing element placed on both sides of the gasket. Allows low pressure sealing).

Isolating Bolt Sleeves

  • Polyester Film
  • Polyethylene
  • Phenolic
  • Nomex® (by DuPont)
  • G7 Silicone Glass
  • G10 Epoxy Glass
  • Isoval 11 Epoxy Glass

Isolating Washers
(3mm thick as standard, other thicknesses available upon request).

  • Glass Clad Phenolic
  • G7 Silicone Glass
  • G10 Epoxy Glass
  • Isoval 11 Epoxy Glass

One Piece Sleeves and Washers

One piece sleeve and washers are typically moulded from acetal resin which limits them to operating in environments where they are not expected to see prolonged exposure to temperatures above 80ºC. To compensate for this, AG is also able to machine custom one piece sleeve and washers for more demanding applications from our range of electrical insulation tubes. For more information on this option, please contact your local AG branch.