Spiral Wound Gasket

Spiral Wound Gasket

Spiral wound gaskets are high-performance sealing components used in industrial piping and valve connections. Alternating metal strips and non-metallic filler provide resistance to pressure, temperature and corrosion.

Structure and Function

Winding element: V-shaped or W-shaped metal strips, such as 304 or 316 stainless steel, are wound with graphite or PTFE filler to form a multilayer sealing structure with resilience and a self-tightening effect.

Inner ring: Provides support, protects against erosion by the medium and assists positioning.

Outer ring: Centers the gasket and prevents excessive compression, particularly in high-pressure applications.

Filler: Graphite, asbestos and other materials are selected according to chemical compatibility.

Main Types

Type A (basic): Without inner or outer rings; used with tongue-and-groove flanges at low to medium pressure.

Type B (inner ring): With an inner ring; used with male-and-female flanges and highly corrosive media, including pharmaceutical and electroplating applications.

Type C (outer ring): With an outer ring; used with raised-face flanges below 6.3 MPa.

Type D (inner and outer rings): Used with raised-face flanges in high-pressure petroleum and chemical piping.

Materials and Performance

Metal strips: Commonly 304 or 316 stainless steel; the source specifies temperature resistance up to 450°C and pressure resistance up to 160 bar.

Fillers: Graphite for high temperatures, PTFE for corrosion resistance and asbestos for specific service conditions.

Benefits: Good resilience under temperature and pressure fluctuations and vibration, with relatively low demands on flange sealing-surface precision.

Applications

Petroleum, chemical processing, power generation and pharmaceutical industries.

High-pressure piping: Steam pipelines and oil and gas transmission.

Corrosive media: Acid and alkaline liquid transfer, with Type B specified in the source.

Equipment: Flanged connections on valves, heat exchangers and manholes.

Installation

Clean flange faces and remove contaminants and scratches to avoid gasket damage.

Tighten bolts gradually in a diagonal sequence for uniform loading.

Control compression on outer-ring gaskets to prevent deformation.

Selection

Select the construction and materials for the service conditions. The source recommends Type D for high-pressure steam and Type B with 316 stainless steel and graphite filler for highly corrosive service.