How to choose high performance hydraulic valve introduction

There are two types of high performance hydraulic valves that are commonly used:
Servo characteristic proportional valve
Also known as high frequency proportional valve or proportional servo valve. This type of valve is used more. The ±10V control signal must be selected during the selection (the 4-20mA control signal cannot be selected).
2. Servo valve (current drive)
This type of valve is called a servo valve from the start, and requires a current input to drive, for example, a drive current of ±50 mA. When the RMC controller is used with a servo valve, a voltage to current mode is required.
Piece. The VC2124 module produced by DELTA USA can convert two ±10V signals into two ±100mA current-driven servo valves.
Servo characteristic proportional valve
In order to achieve excellent performance, easy commissioning and reliable equipment, DELTA USA recommends the use of zero-open linear valves and valves with integrated circuit boards.
The RMC75E and RMC150E are capable of supporting non-linear valves (with an inflection point), but require additional parameter settings for commissioning. Linear valves are easier to use.
Linear valve:
The linearity of the valve means that the relationship between flow and control commands is linear (at least within ±8V)
If the valve selection data is used in terms of bending, inflection points, gradual changes, etc., the characteristics of the valve indicate that the characteristics of the valve are non-linear, and such a valve should be avoided as much as possible.
Zero opening valve:
This means that the mechanical characteristics of the valve port allow the valve to flow as soon as a voltage is applied to the valve.
The board is integrated in the valve:
With this valve, the user does not have to worry about the installation and wiring of the board. Usually, for a good valve, the user does not have to make any adjustments to the board section.
important hint:
Generally speaking, it is not worth the loss to choose a valve with overlapping or dead zones at the valve port and a non-linear valve for closed-loop control. It must be avoided when selecting the type. The recommended servo characteristic proportional valves are as follows. The following are some of the most successful valves used with the US DELTA RMC controller. Many valves offer ±10V or 4-20mA inputs. Be sure to choose a valve with ±10V control signal. The recommended servo characteristic proportional valves are as follows. The following are some of the most successful valves used with the US DELTA RMC controller. Many valves offer ±10V or 4-20mA inputs. Be sure to choose a valve with ±10V control signal.

Bosch Rexroth (Bosch Rexroth)
4WRPEH: Specifications NG6 and 10. Be sure to specify the valve with a linear option.
Parker
D1FP and D1FP*S: Specifications NG6 and D04. Be sure to select the ±10V control signal option.
Atos (Atos)
DLHZO and DLKZOR: Specifications NG6 and 10. Linear valves must be selected. DELTA also recommends the type with the TE option, ie the integrated circuit board into the valve body.