ASME B16.20 SS316 spiral wound gaskets are one of the most dependable sealing components used in industrial flange systems. Their unique metal–nonmetal composite structure allows them to maintain tight, leak-free performance under high temperature, high pressure, and corrosive service conditions. In modern piping systems, a flange connection is only as reliable as the gasket installed between the faces, which is why SS316 Spiral Wound Gaskets have become a preferred choice across the oil & gas, chemical, power generation, and marine industries.
Spiral Wound Gaskets
Spiral wound gaskets are manufactured by alternately overlapping and spirally winding high-quality SUS304, SUS316 (“V”-shaped or “W”-shaped) metal strips and other alloy materials with flexible materials such as graphite, asbestos, PTFE, and asbestos-free materials. The metal strips are secured at the beginning and end points via spot welding.
Among semi-metallic gaskets, metal wound gaskets offer the best resilience. Their structural density can be tailored to different clamping force requirements, with inner and outer steel rings controlling maximum compression. These gaskets do not demand high surface precision from the flange sealing surfaces they contact.
Metal wound gaskets are particularly suitable for applications involving uneven loads, prone to joint relaxation, with periodic temperature and pressure changes, or subject to impact or vibration. They serve as ideal static sealing elements for flanged connections in valves, pumps, heat exchangers, towers, manholes, handholes, and similar equipment.
Structural Materials for Metal Wound Gaskets
| Packing Material | steel strip | Inner Ring | Outer Ring | Temperature （℃） | Maximum operating pressure （kg/cm2 ） |
| Asbestos Wrapping | SUS 304 | Carbon steel | Carbon steel | -200~550 | 250 |
| Graphite Wrapping | SUS 316 | SUS 304 | SUS 304 | -150~450 | 100 |
| PTFE Wrapping | SUS 316L | SUS 316 | SUS 316 | 240~260 | 100 |
What Are SS316 Spiral Wound Gaskets?
SS316 in Spiral Wound Gaskets does not refer to a solid gasket, but rather serves as the “spring skeleton” for the gasket. It is rolled into a thin, narrow metal strip (with a V-shaped or W-shaped cross-section) that provides mechanical strength and the primary seal. This strip generates a “spring” rebound force that compensates for stress relaxation caused by bolt creep and thermal expansion/contraction, maintaining the sealing pressure to prevent leakage.
ASME B16.20 Spiral Wound Gasket
An ASME B16.20 Spiral Wound Gasket is a type of metallic gasket specified by the ASME B16.20 standard for sealing flange connections. It is constructed by spiral-winding alternating layers of a metal strip and a resilient filler material to provide excellent elasticity and sealing performance under varying temperatures and pressures. These gaskets are commonly reinforced with inner and/or outer metal rings to aid in centering, prevent over-compression, and improve resistance to buckling. The ASME B16.20 standard defines the dimensions, materials, tolerances, and markings to ensure compatibility and consistent performance with flanges covered under ASME B16.5 and related flange standards.
ASME B16.20 Gasket Material Configurations
| Winding / Inner / Outer Ring Material Combinations | Maximum Temperature | ASME B16.20 Colour Coding |
| Carbon Steel | 500⁰C | Silver |
| 304 Stainless Steel | 550⁰C | Yellow |
| 316/L Stainless Steel | 550⁰C | Green |
| 316 Ti Stainless Steel | 650⁰C | Light Blue |
| 321 Stainless Steel | 650⁰C | Turquoise |
| 347 Stainless Steel | 650⁰C | Blue |
| Duplex | 800⁰C | – |
| Nickel 200 | 600⁰C | Red |
| Monel 400 | 600⁰C | Orange |
| Titanium | 350⁰C | Purple |
| Hastelloy B-2 | 450⁰C | Brown |
| Hastelloy C-276 | 450⁰C | Beige |
| Inconel 600 | 950⁰C | Gold |
| Inconel 625 | 450⁰C | Gold |
| Inconel X-750 | 1000⁰C | Light Grey |
| Incoloy 825 | 450⁰C | White |
Flange Face Type Matching
•Raised Face Flange: The most common configuration, requiring gaskets with alignment rings to prevent excessive compression.
•Ring Joint Flange: Uses gaskets without inner/outer rings or with inner rings only, sealed within a ring groove.
•Large Face/Full Face Flange: Typically requires gaskets with inner and outer locating rings.
Key Selection Parameters
•Standards: Compliant with ASME B16.20, EN 1514-2, DIN 2697, etc.
•Dimensions: Must precisely match the flange’s nominal diameter, pressure rating, and sealing face dimensions.
•Packing Material: Selected based on medium and temperature (e.g., graphite for high temperatures, PTFE for strong corrosion).
Steps for Selecting Spiral Wound Gaskets
•Confirm flange standards, grades, dimensions, and sealing face types.
•Determine medium composition, temperature, and pressure parameters.
•Select the most suitable packing material type based on the above conditions.
•Choose gaskets with correctly matched center rings (e.g., carbon steel) to ensure installation alignment.
Quality Control & Testing
•Dimensional Accuracy Check
•Compression and Recovery Testing
•Leakage Test Under Pressure
•Material PMI Analysis for SS316
Key Advantages of SS316 Spiral Wound Gaskets
✅Excellent Corrosion Resistance — Suitable for seawater, acids, and chloride-containing fluids.
✅High Temperature Stability — Maintains sealing integrity up to around 550°C when used with graphite filler.
✅Outstanding Mechanical Strength — Metal reinforcement resists blowout under high pressure.
✅Superior Recovery Performance — Compensates for flange surface irregularities and thermal movement.
✅Compatible With Major Flange Standards — ASME B16.5, ASME B16.47, EN 1092-1, etc.
We are professional in manufacturing and exporting flanges in various materials.
