Under what circumstances can constant pressure variable pumps be applied to better utilize their energy-saving effects?
Low pressure maintains full flow output for fast movement (the pump is equivalent to a dosing pump in this process).
No output flow when the set value is reached, to realize the function of holding pressure.
Before the holding pressure value is reached to realize the high pressure on the load push, that is, high pressure slow feed movement.

(1) It must be ensured that the Rexroth Pilot Operated Check Valve has sufficient control pressure and that no loss of control pressure is allowed. Attention should be paid to whether the control pressure meets the requirements for reverse opening. If the control of the Rexroth Pilot Check Valve leads to the main system, the influence of the change in the pressure of the main system on the pressure of the control oil circuit should be analyzed, so as to avoid malfunctioning of the Rexroth Pilot Check Valve.
    (2) According to the position of Rexroth Pilot Check Valve in the hydraulic system or reverse out of the oil chamber after the liquid flow resistance (back pressure) size, a reasonable choice of Rexroth Pilot Check Valve structure (simple or compound) and oil drainage (internal or external leakage). For Rexroth internal leakage type pilot operated check valve, when the reverse oil outlet pressure exceeds a certain value, the hydraulic control part will lose control, so Rexroth internal leakage type pilot operated check valve is generally used for reverse oil outlet cavity without back pressure or back pressure smaller occasions; and Rexroth external leakage type pilot operated check valve can be used for reverse oil outlet cavity back pressure higher occasions, in order to reduce the small control pressure, saving control power.
    (3) Use two Rexroth Pilot Operated Check Valves or one Rexroth Dual Pilot Operated Check Valve to realize
    Hydraulic cylinder locking hydraulic system, should pay attention to the selection of Y-type or H-type neutral function of the Rexroth directional valve to ensure that the neutral Rexroth Pilot Operated Check Valve control port pressure can be immediately released, the Rexroth check valve immediately closed, the piston stops. If O-type or M-type function, in the Rexroth directional valve to the neutral position, due to the Rexroth Pilot Operated Check Valve control cavity pressure oil is closed, Rexroth Pilot Operated Check Valve control oil circuit still exists pressure, so that the Rexroth Pilot Operated Check Valve is still in the open state. And can not make it close immediately, the piston can not be stopped immediately, resulting in the phenomenon of tampering. Until the internal leakage by the Rexroth directional valve so that the control cavity pressure relief, Rexroth hydraulic check valve can be closed, affecting its locking accuracy. But the selection of H-type center function should be very careful, because when the Rexroth hydraulic pump flow through the discharge pipe, if encountered in the discharge pipeline is long or local obstruction or other reasons and local friction resistance (such as the installation of low-pressure filters or pipe joints, etc.), may make the control piston by the control of the pressure is high, resulting in the Rexroth hydraulic check valve can not be closed to make the hydraulic cylinder malfunctioning. y Y-type center function will not form this result.
    (4) The flow rate during operation should match the rated flow rate of the Rexroth valve.
    (5) When installing, do not confuse the main oil port, control oil port and drain port and recognize the positive and negative direction of the main oil port, so as not to affect the normal operation of the hydraulic system.
    (6) Rexroth hydraulic check valve with unloading spool is only applicable to the reverse oil flow is a closed cavity, such as a Rexroth hydraulic cylinder cavity or accumulator. The pressure in this closed chamber can be relieved by releasing a very small amount of flow. The reverse flow is generally not connected to a continuously supplied hydraulic source. This is because the Rexroth unloading valve spool open flow area is very small oil speed is very high, the pressure loss is very large, coupled with this time the hydraulic source of continuous supply of oil, will lead to reverse pressure can not be down, need a lot of hydraulic pressure to make the Rexroth pilot operated check valve main spool open. If the oil pressure in the control pipeline is small at this time, there will be a failure to open the Rexroth hydraulic check valve.