The spiral wound gasket depends upon the mechanical characteristics of a formed metal spiral strip, rather than the compressive virtues of more traditional gasket materials. This makes it particularly suitable for low or fluctuating bolt loads. The sealing strips, or fillers, are usually graphite, although other materials such as Teflon® may be used, the windings are always s/ steal. For this type of gasket to work the spiral must not be over compressed, hence one of two types of compression control is usually used.
1.
The completed gasket is fitted into a steel ring of specific thickness. When the gasket is fitted into a flange and the bolt load is applied, flange closure is governed by the outer steel ring of the gasket. To further improve the pressure rating of the spiral wound gasket, a steel ring may be added to the inside. This also protects the windings ( particularly the filler) , from contamination, or attack by, the product.
2.
The second usually compression control is not fitted to the gasket at all, but engineered into the flange. These Gaskets are called Unsupported Spiral Wound Gaskets.
METAL WINDING STRIP
Stainless Steel 316L
Stainless Steel 304
Stainless Steel 309
Stainless Steel 310
Stainless Steel 316Ti
Stainless Steel 321
Stainless Steel 347
Monel 400
Nickel 200
Inconel 600
Inronel 625
Inconel X750
Incoloy 800
Incoloy 825
Hastalloy B2
Hastalloy C276
Titanium
FILLER MATERIALS
Treated Asbestos Fiber
Non-Asbestos Fiber
P.T.F.E
Graphite
Ceramic
Aluminum
GUIDE RING MATERIALS