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Ball Valve Installation and Maintenance

Blog,Valves Study | Oct.19.2020

There are manual ball valves, pneumatic ball valves, electric ball valves


1. Installation of ball valve

Preparation before installation:

  • The pipelines before and after the ball valve are ready. The front and rear pipes should be coaxial, and the sealing surfaces of the two flanges should be parallel. The pipeline should be able to bear the weight of the ball valve, otherwise the pipeline must be equipped with proper support.
  • Purge the pipelines before and after the valve to remove the oil, welding slag and all other impurities in the pipeline.
  • Check the mark of the ball valve to find out that the ball valve is intact. Fully open and close the valve several times to confirm that it is working properly.
  • Remove the protective parts on the connecting flanges at both ends of the ball valve.
  • Check the valve hole to remove possible dirt, and then clean the valve hole. Even small foreign matter between the valve seat and the ball may damage the seat sealing surface.


  • Install the valve on the pipeline. Either end of the valve can be installed on the upstream end. The valve driven by the handle can be installed at any position on the pipeline. But the ball valve with gear box or pneumatic driver should be installed upright, that is, installed on a horizontal pipeline, and the driving device is above the pipeline.
  • Install a gasket between the valve flange and the pipeline flange according to the pipeline design requirements.
  • The bolts on the flange should be tightened symmetrically, successively and evenly.
  • Connect the pneumatic pipeline (when a pneumatic driver is used).


2. The maintenance of the ball valve

  • It is necessary to find out that the upstream and downstream pipelines of the ball valve have indeed relieved the pressure before disassembling.
  • Care must be taken to prevent damage to the sealing surface of parts, especially non-metal parts, when disassembling and reassembling. Special tools should be used when removing O-rings.
  • The bolts on the flange must be tightened symmetrically, gradually and evenly during assembly.
  • The cleaning agent should be compatible with the rubber parts, plastic parts, metal parts and working medium (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean metal parts. Clean non-metal parts with pure water or alcohol.
  • The decomposed individual parts can be cleaned by dipping. Metal parts with non-metal parts that have not been decomposed can be scrubbed with a clean, fine silk cloth impregnated with cleaning agent (to prevent fibers from falling off and adhering to parts). When cleaning, remove all grease, dirt, glue, dust, etc. adhering to the wall.
  • Non-metal parts should be taken out of the cleaning agent immediately after cleaning, and should not be soaked for a long time.
  • After cleaning, it needs to be assembled after the cleaning agent of the washed wall surface is volatilized (can be wiped with silk cloth not soaked in cleaning agent), but it should not be left for a long time, otherwise it will rust and be contaminated by dust.
  • New parts also need to be cleaned before assembly.
  • Use grease to lubricate. Grease should be compatible with ball valve metal materials, rubber parts, plastic parts and working medium. When the working medium is gas, special 221 grease can be used. Apply a thin layer of grease on the surface of the seal installation groove, apply a thin layer of grease on the rubber seal, and apply a thin layer of grease on the sealing surface and friction surface of the valve stem.
  • Metal chips, fibers, grease (except those specified for use), dust, other impurities, foreign objects, etc., should not be allowed to contaminate, adhere or stay on the surface of the parts or enter the cavity during assembly.

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