FLANGE INSULATION KITS

In order to maintain the full integrity of a pipeline cathodic protection system, a pre-requisite is that the pipeline is electrically isolated from other structures. One of the main reasons for this is to prevent current drainage. In the case of pipelines, well casings and similar construction, insulation can be actioned by installing Insulating Flange Kits or Insulating Joints.

When using Insulating Flange Kits, the material recommended is a neoprene coated phenolic either as a full face or ring joint, used in conjunction with insulating bolt sleeves which can be supplied in sufficient thinness to permit the use of standard bolts provided that there is a clearance of 3 millimeters between bolt diameter and bolt hole. Tufnol or similar material washers are also used to isolate the bolt and nut head from the flange although in practice it is only necessary to isolate on one side. It is important that the gasket material used should have a high electrical resistance in conjunction with rigidity but at the same time permit sufficient compression by tightening up to overcome any problems of leaking joints. It is particularly necessary to over-wrap the whole joint, immediately after making, in order to prevent dirt and moisture ingress between the flange end faces or between the heads of the nuts and bolts and the pipe itself. Wherever possible this type of connection should be pre-assembled in a works and checked for insulation prior to insertion on site.

Standard Flange Insulation Kit

Unless otherwise specified shall consist of the following:

Included Materials

Each set consist of the following:

• Gasket complies to  ASTM B16.2 ( Neoprene Faced Phenolic)  or other
• Insulating Sleeve ( Polyethylene ) or other
• Insulating Washers (Reinforced Phenolic)  or other
• Mild steel Washers   

Further Protection

To prevent short circuit in flanges caused by the ingress of conductive matter between the flanges faces, it is recommended that self adhesive PVC tape be wrapped around the outside of the flange for both types  specially for F type of flange insulating gaskets.

More infirmation please see following links

EDO-DRG-COE-COR-INT-XXX-013-562-689-Rev-A -600 CLASS F TYPE-INSULATION FLANGE.pdf
EDO-DRG-COE-COR-INT-XXX-015-557-684-Rev.A-150 CLASS E TYPE-INSULATION FLANGE.pdf
EDO-DRG-COE-COR-INT-XXX-015-558-685-Rev.A-150 CLASS F TYPE-INSULATION FLANGE.pdf
EDO-DRG-COE-COR-INT-XXX-015-559-686-Rev.A-300 CLASS E TYPE-INSULATION FLANGE.pdf
EDO-DRG-COE-COR-INT-XXX-015-560-687-Rev.A-300 CLASS F TYPE-INSULATION FLANGE.pdf
EDO-DRG-COE-COR-INT-XXX-015-561-688-Rev.A-600 CLASS E TYPE-INSULATION FLANGE .pdf
EDO-SPC-COE-COR-INT-XXX-014-214-242-Rev-A Flange Insulation Kits(Catalogue).pdf