The installation quality of flange connections directly determines the sealing performance and service life of piping systems. Even high-quality flange products can cause leakage if improperly installed. Correct installation and maintenance procedures are key to ensuring long-term reliable operation of flange connections.
Pre-installation preparation is crucial. Before installation, the flange sealing faces and gaskets should be thoroughly inspected to confirm there are no defects affecting sealing performance-. Protective grease and contaminants on the sealing faces should be removed. Gaskets must be new, clean, and dry, and should be checked for defects or damage before use-. Old gaskets cannot be reused-. Before installation, confirm that the gasket size and pressure rating match the flange markings.
Bolt selection and installation also have strict requirements. Bolts connecting flanges should pass freely through bolt holes. The same flange connection should use bolts of the same specification, with consistent installation direction. Bolts should be tightened symmetrically-—meaning tightening in a star pattern rather than sequentially around the circumference. After tightening, bolts and nuts should be flush or protrude by an appropriate length-. No more than one washer should be used per bolt.
Lubrication and anti-loosening treatment are equally important. Anti-seize compound should be applied to threads during installation to prevent thread galling at high temperatures. Washers should be used to prevent loosening caused by vibration. For vertical pipelines, positioning bolts may be installed on the bottom flange beforehand to prevent gasket slippage.
Post-installation inspection is the final quality checkpoint. After flange installation, confirm that all bolts and nuts are uniformly tightened-. After tightening, flanges should fit closely together without gaps.
Regular maintenance is equally important for long-term reliable operation of flange connections. During operation, regularly inspect flange connections for signs of leakage, check bolts for loosening, and check gaskets for aging or damage. For plastic flange connections, bolts should be retightened after a certain interval following installation.
Following standardized installation and maintenance procedures maximizes flange performance, extends service life, and ensures safe piping system operation.
All data are sourced from publicly available sources and are provided for learning, communication, and reference purposes only. If there are any errors, please contact for correction. Please make your own judgment, this website assumes no responsibility.