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.