Metal Wound Gaskets: Manufacturing Process and Key Considerations
In modern industry, metal wound gaskets are essential sealing components, widely used in petrochemical, power, and mechanical manufacturing sectors. The precision of their manufacturing directly affects their sealing performance and service life. This article provides a detailed overview of the manufacturing process, material selection, process control, and inspection of metal wound gaskets, helping industry professionals better understand this critical component.
Manufacturing Process of Metal Wound Gaskets
The production of metal wound gaskets involves four fundamental steps: slitting, forming, winding, and spot welding. For reinforced ring-type gaskets, ring making and assembly are also required. Each step is interconnected, and the quality of every stage impacts the final performance of the gasket.
1. Slitting
Slitting is the first step, where raw metal strips are cut into precise widths. The metal is guided through upper and lower cutting knives designed for pure shearing, producing flat, burr-free strips. Modern processes use automatic winding devices to maintain strip tension and flatness, ensuring consistent quality for subsequent forming and winding.
2. Forming
Forming converts the flat metal strip into a shape suitable for winding. Strips are guided through forming wheels, which are precisely designed to produce flat, symmetrical strips without twists. Proper forming ensures the mechanical properties of the wound gasket meet stringent standards.
3. Winding
Winding is the core step, where formed metal and non-metal strips are spirally wound on a dedicated fixture. Key process parameters include tension and clamping force, which directly affect the gasket's density and uniformity. Empty turns of metal strips are added at the beginning and end of winding for structural stability, with adjustments for large-diameter gaskets or reinforced rings.
4. Spot Welding
Spot welding stabilizes the wound structure. High-frequency pulse spot welding machines ensure uniform welds, proper spacing, and sufficient strength without burning through the strips.
5. Ring Making and Assembly (for Reinforced Ring-Type Gaskets)
Reinforcement rings are fabricated from cold-rolled plates via punching, cutting, bending, or welding. Inner rings match the metal strip material, while outer rings are typically made from Q235 steel with rust prevention. Assembly involves careful insertion and alignment of the rings, ensuring the gasket body can float appropriately without damaging the sealing surface.
Selection of Raw Materials
Material choice is fundamental to gasket quality:
1. Metal Strips:
Cold-rolled stainless steel strips, 0.15–0.25 mm thick, 80–100 mm wide, with hardness Hv≤200 (preferably 160–180). Strips must be smooth, crack-free, and rust-free.
2. Non-Metal Filler Strips:
Options include special asbestos, flexible graphite, and PTFE (0.3–0.8 mm thick). Properties must comply with relevant standards. Flexible graphite should have 99.9% carbon content and minimal impurities; PTFE should be high-purity, preferably imported.
3. Reinforcement Rings:
Inner rings typically match the metal strip; outer rings are often Q235 steel with anti-rust treatment. Material selection may vary based on user requirements.
Control of Process Parameters
Tension and clamping force during winding are critical for gasket uniformity and performance. Advanced winding equipment allows continuous adjustment, ensuring consistent density and stability, especially for large-diameter or wide-faced gaskets. Typical empirical ranges: clamping force 200–450 N, tension 10–30 N.
Size and Appearance
- Thickness and diameter must comply with standard tolerances.
- Pressing wheel groove design controls gasket thickness during winding.
- Displacement sensors measure diameter, control empty turns, and automate spot welding.
- Finished gaskets should have no exposed metal, uniform non-metal protrusions, aesthetically pleasing welds, and correct floating of reinforcement rings.
Inspection
Inspection includes factory inspection (size and appearance) and type inspection (compression, rebound, stress relaxation, nitrogen sealing, etc.). Regular testing ensures consistent quality and helps identify process adjustments when defects are found.
Conclusion
The manufacturing of metal wound gaskets is a complex, meticulous process requiring precise control at every stage—from material selection to final inspection. By following advanced manufacturing techniques and rigorous quality control, high-performance gaskets can be produced to meet the demanding requirements of modern industry. Understanding these processes provides valuable insight for engineers and practitioners in the sealing and industrial components sectors. It's important to know about Google SEO to help your website rank higher in search results.
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