Spiral Wound Gasket Descriptions
Selecting the right semi-metal gasket starts with understanding your application.
Spiral Wound Gasket Styles
The basic spiral wound gasket designs originally were originally conceived by Flexitallic in 1963. Today, Flexitallic is still the market leader, but with more competition than ever. We offer Lamons, Leader, FMI, 3S and other manufacturers of high-quality ISO semi-metallic spiral wound gaskets.
Understanding gasket design starts with understanding your gasketing application. Always consider where the pressure is coming from. Spiral wound gaskets sealing high-pressure applications will require an outer ring for pressure containment. Metallic gaskets in vacuum applications will require an inner ring to prevent the windings from collapsing. When the application requires pressure and vacuum containment inner and outer rings are required. In flanges with a tongue and groove design require only windings and filler, the flange provides the pressure containment.
The second critical design element is selecting the right sealing filler, and metallurgy.
STYLE: ASP-CG Spiral Winding with Outer Guide
Description Detail: The ASP-CG is the most common profile of spiral wound gasket and used extensively in ANSI B16.5 flanges. The gaskets consist of a metal guide ring (or sometimes referred to as a centering ring) and a spiral wound sealing element. This profile is normally used in raised and flat faced flanged. The outer ring is often made of carbon steel (painted or zinc plated to prevent corrosion) but can be made of alloys for higher temperature and more severe medium applications.
STYLE: ASP-R Spiral Winding Only
Description Detail: This style of gasket consists of the winding/sealing element only. It has no guide ring (centering ring) or inner ring. It is most commonly used in tongue and groove and male/female flanges.
STYLE: ASP-IR Spiral Winding with Inner Ring
Description Detail: This gasket is similar to the ASP-R, however, it has an inner ring. Its application is similar to the ASP-R.
STYLE: ASP-CGI Spiral Winding with Outer Guide and Inner Ring
Description Detail: This gasket is identical to the ASP-CG, however an inner ring has been inserted to enhance gasket performance. The inner ring is added to prevent the possibility of the gasket imploding into the pipe during installation, to protect the sealing element from extreme temperatures and mediums, fill the void between flanges to prevent erosion of the flange, and to reduce the possibility of failure. The inner ring is normally made of the same alloy as the winding. The DIN 2699 standard German) specifies inner rings in all spiral wound gaskets. Inner rings are required for gasket with PTFE filler according to ASME B16.20 standards, and considered important for graphite fillers. This profile is normally used in raised and flat faced flanges.
STYLE: GSI-HF Kamm-Sprial
Description Detail: Designed so seal Hydrofluoric Acid (HF) and other critical chemical applications. The gasket contains both spiral-wound and Kamm profile technologies. It occupies all the space from the bore of the pipe to the outer diameter of raised face flanges.
Available in a full range of styles and materials, our spiral wound gaskets are manufactured in accordance with ASME B16.20 for use in all industry flanges, including ASME/ANSI B16.5, ASME B 16.47, Series A & B. American Seal & Packing assures strict adherence to these specifications as routine inspection procedures are applied throughout the manufacturing process. In addition, we maintain trace ability of all materials used in our gasket construction to provide material certifications as required.
Choose from the styles above and let us customize an order to fit your individual need.
API Semi Metallic Gaskets
At what point do I need to use a spiral wound gasket rather than
Generally speaking, non-asbestos gasket materials are great for 125 / 150 lb. pipe flanges. Spiral wound gaskets are generally used in applications in 300 lb to 2500 lb flanges. The decision of the type of spiral wound should be based on the location of pressure. Is pressure trying to get in, out, or both.
For more difficult applications consider Kamm Profile gaskets. RTJ gaskets can only be used in RTJ flanges.