Knowledge related to ball valves

Working principle of ball valves

Ball valves can be tightly closed with only a 90 degree rotation and a small turning torque. The completely equal valve body cavity provides a small resistance and straight flow path for the medium. It is generally believed that ball valves are most suitable for direct opening and closing use, but recent developments have designed them to have throttling and flow control functions. The main characteristic of ball valves is their compact structure, easy operation and maintenance, suitable for general working media such as water, solvents, acids, and natural gas, and also suitable for harsh working conditions such as oxygen, hydrogen peroxide, methane, and ethylene. The valve body of a ball valve can be integral or modular.

Application of Ball Valves

In China, ball valves are widely used in industries such as petroleum refining, long-distance pipelines, chemicals, papermaking, pharmaceuticals, water conservancy, electricity, municipal engineering, and steel, playing a crucial role in the national economy. It has a 90 degree rotation action, and the plug body is a sphere with a circular through hole or channel passing through its axis.
Ball valves are mainly used in pipelines to cut off, distribute, and change the flow direction of the medium. They can be tightly closed with only 90 degrees of rotation and a small rotational torque. Ball valves are most suitable for use as switches and shut-off valves, V-shaped ball valves. In addition to paying attention to pipeline parameters, electric valves should also pay special attention to the environmental conditions under which they are used. As the electric device in electric valves is an electromechanical device, its usage status is greatly affected by its usage environment.

Precautions for using ball valves

(1) It is necessary to first verify that the upstream and downstream pipelines of the ball valve have been depressurized before proceeding with disassembly and disassembly operations.
(2) After cleaning non-metallic parts, they should be immediately removed from the cleaning agent and should not be soaked for a long time.
(3) The bolts on the flange must be tightened symmetrically, gradually, and evenly during assembly.
(4) The cleaning agent should be compatible with the rubber parts, plastic parts, metal parts, and working media (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-metallic parts with pure water or alcohol.
(5) Each disassembled ball valve component can be cleaned by immersion. Metal parts that have not yet decomposed non-metallic parts can be wiped with clean, fine and clean silk cloth impregnated with cleaning agent (to avoid fiber detachment and adhesion to the parts). When cleaning, all grease, dirt, adhesive deposits, dust, etc. that adhere to the wall surface must be removed.
(6) When disassembling and reassembling ball valves, care must be taken to prevent damage to the sealing surface of the parts, especially non-metallic parts. Special tools should be used when removing O-rings.
(7) After cleaning, it is necessary to wait for the wall cleaning agent to evaporate (it can be wiped with silk cloth that has not been soaked in the cleaning agent) before assembly, but it should not be left for a long time, otherwise it will rust and be contaminated by dust.
(8) New parts also need to be cleaned before assembly.
(9) Use lubricating grease for lubrication. The lubricating grease should be compatible with the metal materials, rubber parts, plastic parts, and working medium of the ball valve. When the working medium is gas, lubricating grease such as Te221 can be used. Apply a thin layer of lubricating grease to the surface of the seal installation groove, a thin layer of lubricating grease to the rubber seal, and a thin layer of lubricating grease to the sealing and friction surfaces of the valve stem.
(10) During assembly, metal debris, fibers, grease (excluding those specified for use), dust, other impurities, foreign objects, etc. should not be allowed to contaminate, adhere to or stay on the surface of the parts or enter the inner cavity.