The most common spiral wound gasket used inindustrial settings with a wide variety of temperature and pressure conditions
is a spiral wound gasket. They are frequently employed to prevent leaks at
flange joints in the oil and gas, chemical, petrochemical, electrical, and food
industries. Flexitallic designed the spiral-wrapped gasket in 1912 to
accommodate high temperature and pressure changes in US refinery operations.
Spirally wound gaskets are commonly utilizedin a wide range of applications.
High-temperature service applications
Applications using high pressure
Corrosion-causing fluids
Inflammable fluids
Hydrogen
Spiral Wound Gasket MajorComponents
Asemi-metallic gasket is a spiral wound gasket. It is made of a spirally coiled
v-shaped metallic and non-metallic filler material. A spirally coiled gasket is
made up of three major components. These are their names:
Outer Ring: A spiral wound gasket's outer ring, also known as aguide ring or centering ring, is frequently made of carbon steel. The major
function of this device is to center the gasket when it is fitted into a bolted
flange joint.
Inner Ring: The inner ring of a spiral wound gasket is necessarybecause it prevents the windings from bending within the pipe. When a gasket
bends, parts of it are drawn into the pipe and eventually travel through the
piping system, becoming stuck or wrapped around something. Inner rings prevent
this disease and assist to lessen the likelihood of it occurring.
Sealing Element: The sealing element is the component of the spirallycoiled gasket that forms a tight seal to prevent leaking. Windings and filler
material are both included in the sealing component. Spirally coiled gaskets
are often manufactured using a flexible graphite filler material that can
resist high temperatures. Using graphite as a filler material also helps the
gasket resist flange deformation and joint displacement. Another frequent
filler material is PTFE (Polytetrafluoroethylene). PTFE, on the other hand, is
not suitable for use in high-temperature situations. The most frequent winding
materials are stainless steel and Monel.
Spiral Wound Gasket Markings
Variousmarkings on the gasket differentiate spiral wound gaskets. Each mark gives precise
information about the spiral wound gasket standard, which aids in the gasket
selection process.
Thespiral-wrapped gasket's markings offer the following critical information:
Design Code or Standard: The code used to design and manufacture the spiral-wrappedgasket is shown. This gasket displays the ASME B16.20 standard.
Spiral Wound Gasket Information from the Manufacturer: By verifying the manufacturer's name on thegasket, the manufacturer may be easily determined.
Winding and Filling Material: The spiral wound gasket specifies thewinding and filler materials.
Diameter and pressure class: Diameter and pressure class marks on thegasket define the size of the spiral wound gasket as well as the load that the
spiral wound gasket can bear. Spiral wound gasket pressure classes are commonly
150, 300, 400, 600, 900, 1500, and 2500. As the pressure class grows, so does
the spiral-wrapped gasket's capacity to withstand pressure.
Spiral Wound Gasket Thickness
Spirallycoiled gaskets are typically between 3.2 mm and 4.5 mm thick. A thickness of
5.5 mm to 7 mm is suggested for particularly large diameters. The market
provides a diverse range of spiral-wrapped gasket thicknesses ranging from 1.6
mm to 7.2 mm.
Spiral Wound Gasket Pressure Ratings
There are seven pressure rating classes forspiral-wrapped gaskets. They are divided into 150, 300, 400, 600, 900, 1500, and 2500 categories. The size of spiral wound gaskets is determined by the
design criteria. ASME B16.20, for example, has spiral wound gasket sizing
tables in a tabular format that includes all necessary parameters based on
pressure class and pipe size.
