Metal spiral wound gasket
General Features
A metal spiral wound gasket is a semi-metal flat gasket made by spirally winding a metal belt and a non-metal belt. Its characteristics are: compression, good elasticity; multi-channel seal and a certain degree of self-tightening function; less sensitive to the flange sealing surface defects, do not bond flange sealing surface; easy to center, convenient disassembly Can partially eliminate the effects of pressure, temperature changes and mechanical vibration; can maintain excellent sealing performance in a variety of harsh conditions such as high temperature, low temperature, high vacuum, impact vibration and other cyclic alternation.
Description
Specifications
Thickness: 2.5, 3.2, 4.5, 6.5, 8mm, etc.
Nominal diameter: φ10～φ3000mm
Type
Basic, In-Ring, Locating Ring, Inner Ring, and Positioning Ring
Usage
Widely used in petroleum refining, petrochemical, electric power, gas, nuclear power, aerospace, textile, metallurgy, shipbuilding, and pharmaceutical industries. It is used to seal the flange joints of pipelines, valves, pumps, pressure vessels, condensers, heat exchangers, manholes, and hand holes.
Applications
Packing Bands for Temperature and Pressure
| Fill Belt Type | Usage temperature/°C | Maximum working pressure/MPa |
| Flexible graphite | -196~600 | 30 |
| PTFE | -196～260 | 10 |
Plates, Codes, and Applicable Temperatures of Common Metal Strips
| Grade | Code | Working Temperature/°C |
| 06Cr19Ni10 | 304 | -196~700 |
| 022 Cr19Ni10 | 304L | -196-450 |
| 06Cr17Ni12Mo2 | 316 | -196~700 |
| 022Cr17Ni12Mo2 | 316L | -196-450 |
| 06Cr18Ni11Ti | 321 | -196~700 |
Technical Parameters
| Parameter | Unit | Value |
|---|---|---|
| Compression ratio | % | 18~30 |
| Rebound rate | % | ≥17 |
| Stress relaxation rate | % | ≤15 |
| Seal Leakage Rate | cm3/s | ≤1.2×10-5 |
Installation Instructions
Before installation, the flange surface must be carefully cleaned with a brush to ensure that there is no foreign material on the flange surface. Ensure that the flange surface is flat, free from distortion, and scratches that do not affect sealing. Clean the fasteners to ensure that there are no foreign objects between and around the fasteners.
Make sure the mating flange is aligned during installation.
When tightening bolts, the gasket should be evenly stressed and tightened symmetrically.
In the installation process, observe whether the seal surface of the gasket has a radial penetration flaw that affects the seal, and replace the gasket if it is present.
| Type | Code | Applicable flange sealing surface pattern |
|---|---|---|
| Basic | A | Sink surface |
| In-band loop | B | Convex surface |
| With locating ring | C | Face and Full Plane |
| With inner ring and locating ring | D | Face and Full Plane |
Gasket Type and Flange Selection
Dimensional Measurement Range
Diameter Deviation of Inner and Outer Diameter of Sealing Element, Inner Ring and Positioning Ring (Unit: mm)
| Nominal Size | Seal Element | Inner Ring, Positioning Ring | ||
| D2 | D3 | D1 | D4 | |
| ≤200 | +0.5 | -0.8 | +0.5 | -0.8 |
| 250-600 | +0.8 | -1.3 | +0.8 | -1.3 |
| 650-1200 | +1.5 | -2.0 | +1.5 | -2.0 |
| 1300-3000 | +2.0 | -2.5 | +2.0 | -2.5 |
