We supply very high quality spiral wound gaskets of every type and specification.
The sealing element of the spiral wound gasket consists of a V-shaped metal strip spirally wound in combination with a soft sealing filler. The metal strip provides out-standing resilience, while the flexible sealing filler guarantees excellent sealing. Due to this combination of materials, the spiral wound gasket is suitable for sealing under fluctuating temperature and pressure conditions. Depending on the application the spiral wound gasket can be specified with outer and/or inner rings.
Spiral Wound Gasket Properties.
• Spiral wound gaskets are suitable for use across a wide gasket stress range.
• Spiral wound gaskets can be used to seal fluid pressures up to 400 bar and from cryogenic temperatures up to 1000 deg C.
• Spiral wound gaskets are robust and simple to install.
• The outer guide ring simplifies assembly and prevents blow-out of the gasket.
• By combining different winding materials and metals, the gasket can be tailored to suit a wide variety of operating conditions.
• The gasket is easy to remove after service and does not cause damage to the flange faces.
Spiral Wound Gasket Stress Range
Spiral wound gaskets should preferably be mounted within the gasket stress ranges shown in this chart to ensure leak free connections.
GASKET STRESS RANGE
SINGLE SIDE CONFINED
BOTH SIDES CONFINED
Flange Surface Finish
The recommended surface roughness of the flange faces, between which the spiral wound gasket is to be mounted, is 3.2-6.3um Ra(125-250 RMS), also referred to as smooth finish.
Standard Gasket Profiles
|Type R RF1 |
This gasket consists of sealing filler and V shaped metal strip wound in combination. This profile is usually applied to tongue/groove flanges
This gasket has an integral centering ring which ensures fast, accurate centering of the gasket on the raised face flange. Provides additional radial strength to prevent gasket blow-out and acts as a compression stop
For male/female flanges consisting of a wound component fitted with an inner ring to bring the gasket flush with the pipe bore to prevent inward buckling.
|Type SG-IR |
Identical to type SG but also fitted with an inner ring to prevent buckling at the windings.
|Type SG-RTJ |
A standard spiral wound gasket SG type with dimensions tailored to Ring Joints (RTJ) flanges.
This gasket consists of a wound component fitted with a narrow centering ring to ensure correct centering in flush flanges (Eg in heat exchangers)
Guide Rings and Material Selection
Benefits of the Centering Ring
The spiral wound gasket outer centering ring provides the following benefits; - Optimum location between the bolts. Protection of the spiral wound element. Additional security against gasket blow-out.
Acts as compression limiter preventing overloading and over compression of the spiral wound element.
Prevents radial-flow of soft fillers, such as PTFE.
For these reasons it is preferable to use spiral wound gasket with outer centering rings.
The outer ring is marked with nominal size, pressure class, standard and materials.
Benefits of the Inner Ring.
The spiral gasket inner ring provides the following benefits; - Prevents radial-flow of soft fillers, such as PTFE + Graphite. Reduces turbulence-minimising flow resistance. Acts as a heat shield when the spiral wound gasket is subjected to high temperatures.
Inner and outer rings are particularly recommended for use on spiral wound gaskets exceeding class 600lbs, but specifically recommended for high temperatures and pressures to optimise the operational reliability of the spiral wound sealing element. Inner rings are mandatory for PTFE filled spirals.
The material selection for the inner ring and winding metal is usually the same as the flange metal. This prevents corrosion and differential expansion problems. The outer centerIng ring is generally manufactured from carbon steel with an anti-corrosion treatment. However, the ring may also be manufactured in the same metal as the flange to prevent corrosion problems.