PROPERTIES AND APPLICATION Spiral wound gaskets are special semi-metallic gaskets of great resilience, therefore they are very suitable for applications featuring heavy operating conditions. Spiral wound gaskets are manufactured by spirally winding a V-shaped metal strip and a strip of non-metallic filler material. The metal strip holds the filler, providing the gasket with mechanical resistance and resilience. Spiral wound gaskets can be reinforced by an outer centering ring and/or inner retaining ring. The outer centering ring controls the compression and holds the gasket centrally within the bolt circle. The inner retaining ring increases the axial rigidity and resilience of the gasket. Spiral wound gaskets should always be in contact with the flange and should not protrude into the pipe or prolect from the flange.
Spiral wound gaskets can be used for sealing flange loints, manhole and handhold covers, tube covers, boilers, heat exchangers, pressure vessels, pumps, compressors and valves; in industries such as petrochemical, pharmaceutical, shipbuilding, and food processing, in power industries and nuclear power stations. They are ideal for steam, oil, liquids, gases, acids, alkalines, various organic mediums and solvents.
Spiral wound gaskets are produced in several styles and combination of materials to fit the most stringent application. spiral wound gaskets are usually of circular shape, however 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 to 2200 mm and a nominal thickness of 3.2, 4.5 and 6.5mm. Spiral wound gaskets of non-standard dimensions and shapes, and larger diameters are available on request.
The standard thickness of the metallic strip is 0,2 mm.
MATERIALS FOR META LLIC STRIP
ASTM
DIN Material No.
AISI 304
1.4301
AISI 316
1.4401
AISI 321
1.4541
AISI 316 Ti
1.4571
Monel (NiCu30Fe)
2.4360
Filler is normally used for thicknesses from 0,5 mm to 0,6 mm.
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 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 gasket metallic strip.
Manufacturing sizes This limitations are general and can vary according to the special customer
LIMITATIONS FOR MANUFACTURING DIMENSIONS
Thickness s [mm]
Max diameter d3[mm]
Maximum width - bG[mm]
Graphite
PTFE
2,5
300
16
13
3,2
700
22
19
4,5
1150
30
24
6,5
2500
35
d3
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 slightly beyond the metal).
The tolerance of the gasket diameters (d1, d2, d3, d4, s, s1) are stipulated 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. Dimensions The dimensions of the standard SWG meet the ASME, BS and EN (DIN) standards.
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