Correct Installation Steps of Flange

Correct Installation Steps of Flange

Surface Cleaning and Inspection

Thoroughly clean the flange sealing surface,pipe end,gasket and bolts to remove rust,welding slag,oil,dust and other impurities.Check flanges for deformation,cracks or scratch damage on the sealing face.Confirm the flange size,pressure rating and material match the pipeline working conditions.

Pipe Alignment

Align the two flanges to keep them parallel and concentric.Avoid misalignment,deflection and forced assembly.Keep the connection gap uniform to prevent additional structural stress on the pipeline.

Gasket Installation

Place the matched sealing gasket in the center of the flange face.Do not use double gaskets,inclined gaskets or damaged gaskets.Ensure the gasket fits closely with the entire sealing surface for effective sealing.

Bolt Assembly

Install bolts and nuts with unified specifications in cross symmetry.Keep all bolt directions consistent and the exposed thread length even.Do not mix bolts of different lengths or standards.

Tighten Bolts in Stages

Tighten the bolts step by step in a diagonal crossing sequence.Complete pre-tightening,medium tightening and final tightening in 2 to 3 rounds.Never fasten bolts on one side at one time,which will cause flange deformation and leakage.

Re-tightening and Pressure Test

For high-temperature,high-pressure and vibration pipelines,re-tighten the bolts after the equipment runs and temperature stabilizes.Conduct hydraulic or air pressure testing after installation to check for leakage at flange connections.

Anti-corrosion Protection

Carry out anti-rust and anti-corrosion treatment on flange joints,bolts and welding parts to improve durability and service life.