RPTFE (filled polytetrafluoroethylene) gaskets are widely used in sealing applications in the chemical, petroleum, and pharmaceutical industries due to their excellent chemical resistance, low friction, and good compression resilience. Proper installation of RPTFE gaskets is critical to ensuring a successful seal. The following are specific steps and precautions.
Preparation for Installation
First, thoroughly clean the sealing surface to ensure it is free of grease, particles, or scratches. Wipe it with a non-woven cloth dipped in isopropyl alcohol or a specialized cleaning agent to prevent residue from impairing the seal. Inspect the gasket for cracks, deformation, or nicks; minor imperfections may cause leakage. Also, ensure that the flange surface is flat and free of warpage, and that the roughness meets the required level (typically Ra ≤ 3.2μm).
Installation Steps
Lubricant (Optional): Apply a thin layer of silicone-based grease or molybdenum disulfide on both sides of the gasket to reduce frictional damage during installation. Ensure the lubricant is compatible with the media.
Positioning the Gasket: Align the RPTFE gasket with the flange bolt holes and carefully insert it into the sealing groove or directly between the two flange surfaces. Avoid twisting or folding the gasket, and maintain its natural flatness.
Tighten bolts evenly: Tighten the bolts in diagonal order, initially pre-tightening to 30% of the recommended torque and gradually increasing to 100%. A torque wrench is recommended to avoid local overload that could cause gasket extrusion or failure.
Final Inspection: Confirm that all bolts are evenly loaded and the flange clearances are consistent. Gently pull on the edges of the gasket to check for looseness, but avoid excessive force.
Precautions
RPTFE gaskets have a wide temperature range (-200°C to 260°C), but avoid high temperatures during installation, which can cause premature aging. Do not pry with sharp tools to prevent scratching the sealing surface. If the system is subject to severe vibration, it is recommended to install spring washers to help prevent loosening.
Proper installation of RPTFE gaskets can significantly extend seal life and reduce maintenance costs. Following the above procedures will ensure a reliable and secure seal.
