Purpose: Placed between two UPVC flanges, tightened by bolts to achieve a sealed connection. Used to connect valves, equipment, or large-diameter pipe connections that require detachable connections.
Material: Usually rubber (NBR, EPDM), polytetrafluoroethylene (PTFE) or other media-resistant materials.
Installation:
Make sure the end faces of the two flanges are clean, flat, and free of foreign matter.
Place the gasket in the center between the two flanges.
Insert all bolts and put on the nuts by hand.
Tighten the nuts diagonally, crosswise, in batches, and evenly. In the following order:
First time: Tighten all nuts by hand.
Second time: Tighten with a wrench in diagonal order (such as 1-3, 2-4, if there are 4 bolts) to about 30% of the force.
Third time: Tighten again in diagonal order to about 60% of the force.
Fourth time: Finally, tighten in diagonal order to the specified torque (if required) or until the gasket is evenly compacted. Avoid excessive force on one side causing flange deflection and leakage.
Notes:
Choose the right material and size of gasket! It must match the flange size (outer diameter, inner diameter, bolt hole), working medium, temperature and pressure.
Make sure the gasket is intact, without creases or aging.
Tightening the bolts evenly, diagonally and in batches is the key to preventing leakage!
Both ends of the flange-connected pipe must be firmly supported to prevent the bolts from being subjected to additional bending stress.