Flange Isolation Gasket Kits

By reading the following content, you will know much knowledge and information about Flange Isolation Gasket Kits

Why Do We Need Flange Isolation Gasket Kits?

The purpose of flange isolation gasket kits is to isolate the current in the pipeline system so that it does not flow into the pipeline, offer cathodic protection, and help in preventing galvanic corrosion between the flanges on piping flange systems.

Flanges can be one of the most common trouble areas in cathodic protection. Flanges need to be sealed properly to prevent leakage and must be cathodically isolated to prevent stray currents, which can cause excessive corrosion and eventual breakdown of the metal. For these reasons, that is why we need gasket kits for flange isolation.

The gaskets and kits are made according to ANSI B16.5 requirements up to 24″. Above 24″, please specify the details of your flange.

Components of Flange Isolation Gasket Kits

The flange isolation gasket kits include an isolation gasket retainer, isolation sleeves, isolation washers, and steel washers. In the following sections, we will learn more about these components.

Isolation Gasket Retainer

The materials for the isolation gasket retainer can include G10, G10 with an SS316 core, G11, neo-phenolic, plain phenolic, 100% PTFE, and other materials. All the isolation gasket retainers can have a sealing ring.

Sealing Ring

The sealing ring for the isolation gasket retainer can be made from Viton, nitrile, PTFE, EPDM, or spring-energised PTFE.

Isolation Sleeves

The materials for the isolation sleeve can be G10, G11, Mylar, Nomex, or phenolic.

Isolation Washers

The materials for isolation washers can be G10, phenolic, mica, or other materials.

Steel Backing Washers

The steel backing washers are usually zinc-plated carbon steel, as it is cheap. But SS304 or SS316 are also options. Each bolt hole has 2 steel backing washers.

Types of Flange Isolation Gasket Kits

We can manufacture flange isolation gasket kits that have all styles, including Type E (full-face flange), Type F (raised-face flange), and Type D (RTJ ring joint).

Type E Gasket

With precisely cut holes that let the bolts pass through, the full-face gasket retainer of type E flange isolation gasket kits has the same outside diameter as the flange. This design facilitates proper alignment of the gasket during installation and prevents foreign material from shorting the flange insulation.

Type F Gasket

The Type F gasket is designed to only fit the flange’s raised face section. Because the F gasket has no bolt holes, the bolt hole circle’s inner diameter is less than the gasket’s outside diameter, ensuring precise, automatic gasket installation.

Type D Gasket

Type D gaskets are designed to fit into the ring groove of RTJ (ring-type joint) flanges. It comes in both octagonal and basic oval shapes. BX gaskets with pressure ratings up to 15,000 PSI are also available.

Advantages

Due to the many advantages of flange isolation gaskets, we can see them in many areas.

• Provide cathodic protection to prevent the flow of static electricity along the pipeline.
• Prevent galvanic corrosion from the interaction of dissimilar metals.
• Low installation and maintenance costs.
• A large selection of materials is available.
• It can be used with mismatched flanges.
• The sealing ring cannot be left out.
• Little initial torque is required.
• Gaskets up to 144″.
• Competitive price.
• Reusable.

For more information, please contact us. Technical assistance is available upon request.

Application

Flange isolation gasket kits are used in the petrochemical, oil refinery, and offshore seawater environments where a need for a seal and cathodic protection exists.

Recommended Isolating Gasket Bolt Torque Values

ASME B16.5 Recommended Values in [ft-lb]

	150#	150#	300#	300#	400#	400#	600#	600#	900#	900#	1500#	1500#	2500#	2500#
NPS	Rec	Max	Rec	Max	Rec	Max	Rec	Max	Rec	Max	Rec	Max	Rec	Max
1/2	30	45	30	45	30	45	30	45	95	120	95	120	95	120
3/4	30	45	55	90	55	90	55	90	95	140	95	140	95	140
1	30	45	55	90	55	90	55	90	155	220	155	220	155	220
1 1/4	30	45	55	90	55	90	55	90	155	255	155	255	230	350
1 1/2	30	45	95	160	95	160	95	160	230	380	230	380	335	530
2	55	90	55	90	55	90	55	90	155	255	150	245	230	380
2 1/2	55	90	95	160	95	160	95	160	230	380	230	380	335	530
3	55	90	95	160	155	255	95	160	155	255	335	560	470	785
3 1/2	55	90	95	160	155	255	155	255	-	-	-	-	-	-
4	55	90	95	160	155	255	155	255	335	560	470	785	800	1400
5	95	160	95	160	155	255	155	255	470	785	840	1400	1370	2170
6	95	160	95	160	155	255	230	380	335	560	640	1065	2080	2995
8	95	160	155	255	230	380	335	560	640	1065	1085	1805	2080	3155
10	155	255	230	380	335	560	470	785	640	1065	1700	2830	4165	6005
12	155	255	335	560	470	785	470	785	640	1065	2080	3465	5595	8090
14	230	380	335	560	470	785	640	1065	840	1400	3005	4390	-	-
16	230	380	470	785	640	1065	840	1400	1085	1805	4165	6105	-	-
18	335	560	470	785	640	1065	1085	1805	1700	2830	5595	8900	-	-
20	335	560	470	785	840	1400	1085	1805	2080	3465	7320	10730	-	-
22	470	785	840	1400	1085	1805	1370	2280	-	-	-	-	-	-
24	470	785	840	1400	1370	2280	1700	2830	4165	6945	11765	18060	-	-