The three-way valve (7) is used to control the direction of movement of two cylinders. To make table 1 rises, the switching valve 7 is set the right position, the pump 10 hydraulic oil discharged through the check valve 9, and the control valve 8 has a valve 7 to the auxiliary cylinder chamber oil supply rod 4 roller hydraulic repair company, then check valve 6 is opened, the auxiliary chamber rodless cylinder 4 hydraulic oil through the check valve 6,5 flows into the master cylinder rod chamber 3, and the main cylinder rod chamber of the hydraulic oil through the valve 7, two two-way valve 14 and the throttle valve 15 back into the tank 18, so that the auxiliary cylinder piston rod 4, led the decline counterweight 2 3 and the master cylinder piston rod 3 led the table a rise. This process is equivalent to the potential counterweight 2 passed a workbench. Two two-way valve (14) to play a protective role, it works as follows: If the working platform workpiece weight carried by a small rise or carries the work platform or a decline in the hydraulic roller carry great weight of the workpiece repair, if there is no valve (14) where roller hydraulic repair, it is possible to make the secondary master cylinder 3 and 4 cylinder piston velocity surge can not control, and even cause damage to the hydraulic cylinder. Plus valve (14), you can cut off the master cylinder or the auxiliary cylinder that happens when the oil chamber between the rod and the tank, which play a protective role. Roller hydraulic repair quote, Tongchuan roller hydraulic repair, hydraulic repair Chengtong Xi'an Xi'an Chengtong hydraulic repair Limited. Xi'an Chengtong Hydraulic Maintenance Co. (www.huosu360.com) strong, credible, in Xi'an, industrial maintenance, installation and other industries has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead the Xi'an-hydraulic service and you work through into the brilliant, for a better future!