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INSULATION GASKETS KITS

metungtech.com

INSULATION GASKET KITS

The most common problematic area for a Piping/Pipeline System design is flanges. So we have to be doubly sure to seal it properly to prevent flange leakage. At the same time, It must also be insulated catholically so that stray currents which are known behind the undue corrosion and eventual metallic breakdown be prevented. Insulating gasket sets or Flange insulation kits play an important role in such cases.

• They are designed for electrically insulating the flanges.
• They act as an insulator between dissimilar metallic flanges.
• Also, they are used to isolate sections of pipework (dissimilar metals) electrically in the cathodic protection systems; thus preventing the electrostatic charge flow along the pipelines as they remove the possibility of galvanic cell system creation.

Insulating gasket kits can be used in all such places where galvanic corrosion protection and electrical insulation are needed. Common Application areas are piping/pipeline systems with seawater environments, offshore installations, chemical installations, oil refinery pipelines, etc.

Each flange insulation Kit (Refer to Fig. 1) constitutes of

one central flat or oval section gasket,

one insulation sleeve per bolt and

two insulating steel washers per bolt and

two plated steel washers per bolt.

All these components are produced using special materials possessing chemical stability, dielectric properties, and low water absorption so that the purpose is solved. The full sets are packed individually and labeled clearly mentioning the flange size, rating, type, and material combination. Insulation kits are generally available upto 24 inches, but custom-made higher nominal sizes can be produced on the requirement.

Types of Flange Insulating Gaskets

Four major types of gasket isolation kits are available in the market those are designated as F, E, D, & O. Each type of flange kit fits flanges with a specific type of flange face (RF, FF, RTJ).

F Type Gasket

Type F type gaskets are produced to fit the raised face flanges. The inside diameter of the bolt-hole circle is made slightly smaller than the external diameter of the gasket which assures automatic positioning of the gasket. To avoid the accumulation of foreign materials, Special band protectors can be used for the joint assembly to strengthen the cathodic isolation further.  These are manufactured from 1/8″ thick fabric-based phenolic sheets either without coating or a with a nitrile rubber coating on the two faces. Type F gaskets are also available in non-asbestos fibers with high isolation capacity.

E Type gasket

In full-face type, Type “E” Gaskets, the outside diameter of the gasket matches the external diameter of the flanges. So the gasket completely covers the whole flange surface.  There are produced with precision-located bolt holes and are easy to position in the center. This design will prevent foreign material accumulation between the flange faces and thus enhances the isolation properties of the kit. Type E flange insulation kits are available in phenolic, neoprene-faced phenolic, and high-temperature materials.

D Type Gasket

Type “D” Gaskets are manufactured to fit into the ring groove of RTJ flanges (style R, RX, and BX). They are available in medium weave reinforced phenolic and other materials are sized to ANSI specifications available in a basic oval as well as an octagonal shape. This type of gasket is known as an “API ring joint”.

O Type gasket

Type O Gaskets are extra special as they feature an additional sealing element on both sides of the device, generally, PTFE, Nitrile, or Viton Rubber, and are available in both ring and full-face designs (type E and F).

Insulating gasket Material

• All materials should be selected to assure long-term effective sealing and electrical insulation of the flanged joints.
• To take advantage of the best characteristics, sometimes, gaskets are made with combinations of materials.

Normal Gasket materials are G3, G7, Nitrile-Face, Plain Phenolic, G10, Neoprene-faced Phenolic, Klinger, Teflon, Durlon, etc. Popular Sleeve materials are Phenolic, Mylar, Polyethylene, Minlon, or Nomex.  Common washer materials are Phenolic, Steel, G7, G3,  or G10 available as a single washer and sleeve kit, a one-piece washer kit, a double washer kit, or a one-piece double washer kit (Minlon)