Where sections of pipeline need to be electrically isolated from each other for the control and regulation of cathodic protection and electrolytic flow, insulating gaskets are normally used. With 30 years of engineering performance behind it, BAC Corrosion Control markets an extensive range of flange insulating kits, which provide isolating solutions for a wide range of applications.
A standard BAC flange insulation kit comprises a gasket, insulating sleeves, insulating washers and steel washers. The appropriate UNC stud bolts and nuts can also be supplied to make a full kit. Gasket types can be of full face -- Type E -- where the outside diameter of the gasket matches that of the flange on which it will be used, or Type F for raised face flanges.
Neoprene faced phenolic gaskets have long been used as a standard insulating gasket in the gas and oil industries as the soft neoprene rubber provides good sealing qualities. For these gaskets, which BAC supply in either E or F type, neoprene sheets are factory bonded to both sides of a laminate phenolic sheet to give excellent sealing qualities and high electrical resistance. They are suitable for temperatures up to 90ºC.
Plain phenolic gaskets from laminated material can be used for insulating applications up to 120ºC but to obtain an effective seal it is necessary to used standard 1.5 mm thick service gaskets.
“Klingersil”, a top quality material for general use, is a compressed glass fibre jointing with NBR binder. BAC supply gaskets for use with air, steam, oils and fuels, gases including oxygen and potable water applications. The material will withstand a maximum operating temperature of 430ºC.
Other components in the kits include insulating sleeves of spirally wound Mylar, high strength phenolic resin insulating washers, steel washers to BS3410 table 4 and studbolts, with two 2H nuts, to BS4882 UNC.
All the materials used in BAC’s insulating gaskets are selected to provide quality products that will give long term effective flanged joint sealing and electrical insulation. Depending upon application BAC will sometimes combine gasket materials to achieve the best characteristics of each.