What are the technical requirements for the maintenance of the pressure control valve of a four-column hydraulic press?

Technical requirements for the maintenance of the pressure control valve of the four-column hydraulic press

① Clean all the parts to be installed, especially the channels and orifices.

② Both ends of the spring must be ground flat to ensure that both ends are perpendicular to the center line.

③ The sealing steel ball or poppet valve and the valve seat should be well sealed, and kerosene or gasoline can be used for leak test before installation.

④ The spool valve (also called the spool) should move flexibly and unimpeded in the valve body hole.

⑤ The paper gasket of the oil distribution plate of the sealing gasket should be made of oil-resistant paper gasket to ensure smooth oil flow in the channel.

⑥After the hydraulic pressure control valve is assembled, the following performance tests should be done:

a. The hydraulic press manufacturer reminds you that you should loosen all the pressure adjustment screws first, and then re-adjust. At the same time, with the turning of the adjusting screw, when the pressure of the system gradually increases from the lowest to the rated pressure, its pressure should change uniformly without sudden jump and noise.

b. When the pressure control valve is in the unloading state, its pressure shall not exceed 0.15-2MPa.

c. The pressure swing value of the pressure control valve should be less than ±0.2MPa (the pressure relief valve should be less than ±0.1MPa).

d. The pressure loss of the pressure control valve should be less than 0.3MPa.

e. Under the highest working pressure of the pressure control valve, no leakage is allowed at the joints, and the internal leakage should be as small as possible (generally less than 30-100mL/min).