Ball valve installation and maintaince

 Industry news    |      2009-05-04

Ball valve installation and maintaince





First, ball valve installation

1, before installation

(1) The pipeline in front and back the ball valve is ready. Before and after the pipeline should be coaxial, two flange sealing surface should be parallel. The pipe should be able to withstand the weight of the ball valve, otherwise the pipe must be equipped with proper support.

(2) Purge the front and back pipelines of the valve to remove oil, welding slag and all other impurities from the pipeline.

(3) Check the sign of the ball valve and check that the ball valve is intact. Fully open the valve several times to verify that it is working properly.

(4) Remove the protective parts on the connecting flanges at both ends of the ball valve.

(5) Inspect the valve hole to remove any contaminants and then clean the valve hole. Even tiny foreign particles between the seat and the ball may damage the seat sealing surface.

2, Start to install the ball valve

(1) Put the valve on the line. Any end of the valve can be mounted on the upstream side. The lever-operated valve can be installed anywhere on the pipe. However, ball valves with gearboxes or pneumatic actuators should be installed upright, on horizontal pipes with the drive above the pipe.

(2) Install gaskets between the valve flange and the pipeline flange as required by the piping design.

(3) The bolts on the flange must be tightened symmetrically, successively and evenly.

(4) Connect the pneumatic line (when pneumatic drive is used).

3, check the ball valve after installation

(1) Operating the actuator to open and close the ball valve several times shall be flexible and free of stagnation, confirming that it is working properly. (2) Check the sealing performance of the flange joint between the pipe and the ball valve according to the piping design requirements.

Second, the maintenance of the ball valve

General rules for ball valve maintenance:

(1) It must be ascertained that the pressure on the upper and lower pipelines of the ball valve has been removed before the decomposing operation can be performed.

(2) When disassembling and reassembling, care must be taken to prevent damage to the sealing surfaces of parts, especially non-metallic parts. Special tools should be used when removing O-rings.

(3) The bolts on the flange must be tightened symmetrically, gradually and evenly during assembly.

(4) The cleaning agent shall be compatible with the rubber parts, plastic parts, metal parts and working media (eg gas) in the ball valve. When the working medium is gas, metal parts can be cleaned with gasoline. Non-metallic parts are cleaned with pure water or alcohol.

(5) Decomposed individual parts can be cleaned by dipping. Metal parts that remain undecomposed of non-metallic parts may be cleaned with a clean, finely-dipped silk cloth (to prevent fibers from sticking to the parts). Remove any grease, dirt, glue, dust, etc. that adhere to the wall when cleaning.

(6) Non-metallic parts shall be removed from the cleaning agent immediately after cleaning, and shall not be soaked for a long time.

(7) After cleaning, it is required to be cleaned after the wall-washing agent is volatilized (rubbed with unsaturated cleaning agent), but it must not be left for a long time, otherwise it will rust and be contaminated by dust.

(8) New parts must also be cleaned before assembly.

(9) Lubricate with grease. Grease should be compatible with ball valve metal materials, rubber parts, plastic parts and working media. When the working medium is gas, for example, special grease 221 can be used. Apply a thin layer of grease to the surface of the seal mounting groove, apply a thin layer of grease to the rubber seal, and apply a thin layer of grease to the sealing surface and the friction surface of the stem.

(10) Metal dust, fibers, grease (except for the specified use), dust, other impurities, foreign matter, etc. shall not be allowed to be contaminated, adhered or stay on the surface of the part or enter the internal cavity.