A leak-free flange connection is essential for maintaining operational safety and efficiency in industrial systems. Even minor leaks can result in safety risks, environmental concerns, and unplanned downtime. At Hanna Rubber, we understand the importance of proper flange and gasket preparation—and how critical it is to get it right the first time. Below are best practices to help ensure a reliable, long-lasting seal.
Flange and Bolt Preparation: Foundation of a Secure Seal
Cleanliness
Before installing a gasket, thoroughly clean the flange faces. Remove any rust, scale, oil, or debris that could interfere with sealing. Inspect for surface damage such as warping or pitting, which can compromise gasket performance. Use appropriate solvents or cleaning agents to ensure a clean, dry surface.
Gasket Selection and Placement
Choosing the right gasket type depends on application-specific factors such as pressure, temperature, and the type of media being conveyed. Whether using spiral-wound, ring, or full-face gaskets, proper placement is key.
- Always center the gasket between the flange faces.
- Avoid having the gasket overlap into the flange bore.
- In low-temperature applications (below 40°F), consider applying a petroleum-free silicone lubricant to support better sealing.
Flange Installation Guide: ANSI Installation Best Practices
Bolt Installation
- Insert bolts evenly to maintain balanced pressure around the flange.
- Apply anti-seize compound to bolt threads and nuts—especially for stainless steel—to reduce galling and improve torque consistency.
- Hand-tighten bolts using a cross-pattern sequence before applying final torque.
Torquing for Even Compression
Using a calibrated torque wrench, follow a multi-stage tightening process to ensure uniform pressure across the gasket surface:
- Stage 1: Tighten bolts to 30–50% of final torque value.
- Stage 2: Increase torque to 70–80%.
- Stage 3: Tighten to 100% of the recommended final torque.
- Stage 4: Recheck all bolts at full torque to verify even compression.
After pressurization, some applications may require re-torquing within 4 to 24 hours to account for gasket relaxation.
Additional Installation Considerations
- Flange Alignment – Misalignment can cause uneven gasket compression and eventual leakage. Ensure the flanges are properly aligned before tightening bolts.
- System Support – The piping and flanges should be adequately supported to avoid unnecessary mechanical stress on the joint.
- Correct Bolt Selection – Use bolts rated for your specific pressure, temperature, and flange specifications.
- Environmental Awareness – Be mindful of ambient temperatures or chemical exposure that may affect gasket material.
- Torque Tool Calibration – Regularly calibrate torque tools to maintain accuracy and ensure consistent torque application.
Build Leak-Free Systems with Hanna Rubber
Proper gasket installation starts with preparation and ends with precision. By following established ANSI flange installation guidelines and selecting the right materials for your application, you can prevent costly leaks and extend the life of your equipment.
Hanna Rubber offers a wide selection of gasket materials and provides expert guidance on proper installation practices for industrial applications. Contact us today to learn how we can help you improve sealing performance across your operations.