Selection Of Servo Solenoid Valves - Siemens SINAMICS S120 System Manual

3.3.2

Selection of servo solenoid valves

Overview of valve types
The HLA supports servo solenoid valves with integrated electronics (OBE) as well as third-
party valves. The drive is automatically parameterized when the article number is entered.
The valve parameters can also be manually entered.
A valve is selected for a particular application based on the subsequently described criteria.
Servo solenoid or HR servo solenoid valves
HR servo solenoid valves set themselves apart as a result of their higher dynamic
performance, i.e. a higher frequency limit when compared to servo solenoid valves. They
respond with greater sensitivity to setpoint changes especially in the very low signal range.
The use of HR servo solenoid valves is recommended in the following cases:
1. When extremely high contour precision is required in high-speed continuous-path control
machining operations.
2. When very high response sensitivity is required to achieve the best possible positioning
accuracy.
Valve size
The valve size is determined by the maximum flow rate Q
calculated according to the fluid flow law:
Q = v × A
X
v: Maximum drive velocity for extension and retraction
A: associated cylinder surface area
The calculated maximum flow rate must not exceed the valve operating limit. The valve
operating limit is generally specified in the catalog by the valve manufacturer.
Within the valve operating limit, the flow rate that can be achieved with the valve is
calculated as follows:
In practice, the cylinder velocities that can actually be achieved depend on the operating
pressure, the load pressure and flow-specific characteristics of the drive. The dimensioning
is the responsibility of the hydraulic application engineer, who has access to a number of
design calculation and simulation programs.
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Configuration
3.3 Configuring the hydraulics
. This maximum flow rate is
x
39