Proper installation of flange gaskets is critical to ensuring a tight, dependable seal in piping systems. Improper fitting can lead to equipment failures, safety risks, and costly periods of downtime. This guide details the step-by-step process for installing flange gaskets and provides recommendations for selecting the appropriate gasket type to meet diverse application requirements.
Step 1: Select the Appropriate Gasket Type
Flange gaskets are available in several common varieties, including rubber gasket、PTFE gasket、PTFE bonded rubber gasket、metal wound gaskets, oval gaskets, octagonal gaskets, pure fiber gaskets, and metal grooved gaskets. Among these, metal wound gaskets are the most widely used, so they will be the primary focus of this introduction.
Metal wound gaskets are semi-metallic sealing components designed for use in flange connections under medium-to-high pressure and high-temperature conditions. They are manufactured by spirally winding V-shaped or W-shaped metal strips together with flexible filler materials (such as graphite or PTFE) in an alternating pattern. This structure delivers exceptional elasticity and sealing performance. To further improve gasket stability and sealing efficiency, inner rings and/or outer rings can be added based on specific application needs.
Step 2: Clean the Flange Surface
Contaminants such as rust, leftover residue from old gaskets, or oil can compromise the seal and cause leaks. Follow these steps to ensure proper cleaning:
Remove debris using a wire brush or plastic scraper (avoid metal tools, as they may scratch the flange surface).
Degrease the surface with acetone or a suitable industrial solvent.
Inspect the flange for damage: Warped or scratched flanges must be repaired before proceeding with installation.
Expert Insight: According to the Fluid Sealing Association (FSA), inadequate surface preparation is the root cause of 70% of flange leaks.
Step 3: Position the Flange Gasket Accurately
Align the gasket’s center with the flange holes, then carefully place the gasket between the two flanges.
Do not use glue or adhesives unless explicitly recommended by the gasket manufacturer.
For gaskets equipped with locating rings, ensure the rings are properly seated in the flange grooves.
Why This Step Is Critical: As noted in Pumps & Systems Magazine, misaligned gaskets result in uneven compression, which directly leads to leaks.
Step 4: Install and Tighten the Bolts
Insert bolts into the flange holes following a diagonal sequence (this ensures even pressure distribution).
Tighten the nuts gently to secure the gasket, but do not apply the final torque at this stage.
Use a torque wrench to tighten the bolts incrementally in a crosswise pattern, applying 30%, 60%, and finally 100% of the recommended torque in separate stages.
Data-Driven Best Practice: Research published in the International Journal of Pressure Vessels and Piping shows that proper bolt tightening reduces the risk of leaks by 90%.
Step 5: Conduct a Leak Test
Perform an air test to check for bubbles or a hydro test to identify drips—both are indicators of leaks.
For hidden or hard-to-detect leaks, use ultrasonic testing equipment.
Conclusion
Correct flange gasket installation is key to maintaining system safety, operational efficiency, and cost-effectiveness. If you require high-quality gaskets—including metal wound gaskets, oval gaskets, octagonal gaskets, pure fiber gaskets, or metal grooved gaskets—reach out to us for certified, reliable solutions tailored to your needs!