Spiral Wound Gasket

DESCRIPTION

Spiral wound gaskets are manufactured by spirally winding v-shaped metal strip and a strip of non-metallic filler material.
Spiral wound gaskets can be reinforced by an outer centering ring and/or inner retaining ring. Spiral wound gaskets can be used for sealing flange joints, manhole and hand hole covers, tube covers, boilers, heat exchangers, pressure vessels, pumps, compressors and valves.

SHAPE AND CONSTRUCTION

Spiral wound gaskets are usually of circular shape, however we can produce them in other shapes such as: oval, rectangular with round corners, etc. Our standard production program comprises a range of spiral wound gaskets with inner diameters of 10 mm to 3000 mm and a nominal thickness of 3.2mm, 4.5mm and 6.5mm. Spiral wound gaskets of non-standard dimensions and shapes, and larger diameters are available on request.

GASKET STANDARD STYLES

MATERIALS FOR SPIRAL WOUND GASKETS

Metallic Strip

Holds the filler. Standard thickness of the metallic strip is 0.2mm (0.18 inch). Materials for metallic strip are as below table:

Other alloys available on request

Filler

Filler does the sealing with pressing. Filler is normally used for thickness from 0.5mm to 0.6mm. materials used for filler are:

• Flexible graphite 98%
• Flexible graphite 99.85%
• PTFE, E-PTFE
• Ceramic, Mica

Centering Ring

Centering ring controls the compression and holds the gasket centrally within the bolt circle. The centering ring does not come into direct contact with contained fluid. It is normally made of carbon steel and electro plated or painted to avoid corrosion. Other materials are available on request.

Inner Ring

The inner retaining ring increases the axial rigidity and resilience of the gasket. Inner ring is used to avoid excessive.compression due to high seating stress in high pressure service and it is also used to reduce turbulence in the flange area. It is normally made of the same material as the metallic strip.

DIMENSIONS

Sizes

The dimensions of the standard SWG meet the ASME, BS and EN (DIN) standards. Limitations for dimensions are shown in following table:

These limitations are general and can vary according to the special customer requirements

Thickness

The standard manufacturing thicknesses for spiral wound gaskets are: 3.2mm; 4.5mm; 6.5mm (measured across metallic strip not including the filler, which protrudes 0.2-0.3mm beyond the metal).

Tolerances

The tolerances of the gasket diameters stimulated by ASME B 16.20 and EN 1514-2 standards.The gaskets designed for non-standard flanges meet the recommendations by the ASME B 16.20.