Spiral-Max gaskets can be made from a wide variety of profiled alloy containment strips combined with specified sealing composites. Following ASME B16.20 code, the strips are wound around a mandrel specific to the finished gaskets internal dimensions. The gasket’s inside diameter contains, at a minimum, three plies of preformed metal strip without the sealing composite and is spot-welded at least three times at a distance no greater than 3” apart around the inner circumference. The sealing material, also in strip form, is introduced and wound together with the profiled alloy to achieve the total width of the gasket. The external layers, up to three plies, are spot-welded circumferentially with a minimum of three welds.
Designed to achieve an effective seal under the most demanding operating conditions, the Spiral-Max profile is engineered to provide recovery in applications where the load on the gasket may vary due to major temperature fluctuations. While there is not a published standard for the construction of hand-hole and manhole spiral wound gaskets, the industry often categorizes them into pressure ratings 0-999 PSI and greater than 1,000 PSI. The difference between these two designations is the thickness of the sealing composite. a thicker sealing composite results in a lower content of containment strip. Inversely, a thinner sealing composite allows for an increased content of containment strip. The higher the alloy content, the more pressure the gasket can withstand.
The Spiral-Max designation codes for gaskets manufactured utilizing these techniques are:
OG – representing Outer Ring And Gasket Element.
OGI – representing Outer Ring, Gasket Element and Inner Ring.
LP – for hand/man hole gaskets in applications where pressure is less than 999 psi.
HP – for hand/man hole gaskets in applications where pressures exceed 1,000 psi.
HPI – for hand/man hole gaskets in applications where pressures exceed 1,000 psi and the use of a centering ring accurately locates the gasket on the flange face, provides additional radial strength, and acts as a compression limiter.
Style OG and OGI gaskets are individually marked with a 4-letter traceability code trying it to the Material Test Reports of the raw materials utilized in the production of the gasket.
To access material test reports click on this link – MTR’s.