Maintenance of hydraulic system valves and lines

　　1、Maintenance of air-controlled lift valve, limit valve and check valve

　　First lift the carriage up, use the safety support bar to hold up the carriage, and additionally use the auxiliary support bar to strut the carriage. Then disassemble. If the oil pump is faulty and the carriage cannot be lifted, place the lifting handle in the "down" position, lift the front end of the carriage with a crane or chain skid, support the carriage with the support bar and then dismantle.

　　(1) Put the pneumatic control valve lift handle in the "down" position, remove the pneumatic control lift valve, limit valve and check valve inlet and outlet pipes, release the hydraulic oil in the hydraulic cylinder and catch it in a container to prevent loss and pollution of the environment. Then remove the air-controlled lift valve, limit valve, check valve and other valve parts.

　　(2) Clean the dismantled valve parts and oil pipes and oil pipe joints with paraffin or diesel oil, or maintain and replace them.

　　Note: As the valve parts are precision parts, the dismantled parts should be placed carefully and gently to prevent bumping!

　　2、Maintenance of pipelines

　　(1) High-pressure oil pipe.

　　High pressure oil hose includes double braided steel wire layer rubber hose with standard fittings and seamless steel pipe. High pressure rubber hose aging, cracks, debonding, bulging or leakage should be replaced immediately; when assembled, grease (grease) or sealant should be applied to the oil hose joints first.

　　The steel pipe joint is made of ferrule type joint, the ferrule inside the joint must be replaced after disassembly. Otherwise the seal will not be tight.

　　(2) Low pressure oil hose

　　The low pressure oil hose is a rubber oil resistant hose and seamless steel pipe.

　　Seamless steel pipes should be replaced if they cannot be sealed with oil or are deformed by external forces.

　　Rubber hoses should be replaced when they are aged and deformed.

　　3、Check the integrity of the oil hose regularly to prevent the oil hose from breaking or the joint from loosening and causing malfunction.

　　4、After the oil hose is installed, the carriage should be lifted to the highest position, filled with oil in the tank, and exhausted air.

　　The following matters should be noted when dismantling operations are carried out.

　　1, disassembly must ensure that the workplace clean.

　　2、So the parts must be cleaned.

　　3, each moving part should be coated with lithium-based grease before assembly.

　　4, not allowed to use gasoline to clean the rubber seals.

　　5, disassembly and assembly shall not be knocked, impact, so as not to damage the parts.