Specific considerations for ball valve use:
When the ball valve is closed, there is still pressure fluid in the valve body; before maintenance, the pipeline pressure is lifted and the valve is in the open position; before maintenance, the power supply or gas source is disconnected; before maintenance, the actuator is detached from the support; the upper part of the ball valve and the downstream pipeline have indeed been removed before the disassembly and decomposition operation can be carried out. When decomposing and reassembling, we must be careful to prevent damage to the sealing surface of the parts, especially the non-metallic parts. Special tools should be used when taking out the o-ring; the bolts on the flange must be symmetrical, gradually and evenly tightened; 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, metal parts can be cleaned with gasoline (gb484-89). The non-metallic parts are cleaned with purified water or alcohol; the decomposed individual parts can be washed in a dip-washing manner. The metal piece with the undecomposed non-metal part can be cleaned with a clean, fine, very clean cloth with a cleaning agent (to avoid the adhesion of the fibers to the part). All grease, dirt, accumulated glue, dust, etc. adhered to the wall shall be removed at the time of cleaning; the non-metallic parts shall be removed from the cleaning agent immediately after the cleaning of the non-metal parts, and shall not be soaked for a long time; after the cleaning, the surface cleaning agent to be washed shall be evaporated (with the silk cloth without the cleaning agent) to be assembled. It shall not be put on hold for a long time, otherwise it will rust and be polluted by dust; the new parts shall also be cleaned before assembly; and grease shall be used for lubrication.
The grease shall be compatible with ball valve metal, rubber, plastic and working media. For gas, for example, the working medium may be used, for example, in the form of T221 grease. Apply a thin layer of grease to the surface of the seal mounting groove, apply a thin layer of grease on the rubber seal, and apply a thin layer of grease on the sealing surface and the friction surface of the valve stem; the metal chips, fibers, grease (other than those specified for use) and other impurities shall not be allowed during assembly. Foreign matter or the like is contaminated, adhered, or stopped on the surface of the part or into the cavity.