WSR Way Valve

Way Valve, E/H Converter, Proportional Directional Control Valve, Servo-Proportional Valve

Way Valve Type WSR, Proportional Directional Control Valve

Voith electro-hydraulic way valves are proportional directional control valves. They have integrated position control and provide direct control of hydraulic positioning cylinders. The positioning cylinders operate a valve that controls the mass flow needed to drive machinery. Voith way valves ensure very precise and high dynamic control of the mass flow.

Working in conjunction with a hydraulic cylinder, the way valve converts a constant input pressure into a variable stroke. A standard 4 – 20 mA signal specifies the stroke of the positioning cylinder. The major components of a way valve are a 3/3 way hy­draulic unit for single-acting positioning cylinders or a 4/3 way hydraulic unit for double-acting positioning cylinders and a force-controlled electromagnet with integrated position control. An additional pilot valve is not needed with the Voith electrohydraulic way valve.

The way valve features a simple, compact design. This ensures consistent, reliable operation. The Mean Time Between Failures (MTBF) for Voith way valves is over 180 years. Your equipment runs for a very long period of time without unplanned down­time. Availability is increased.

The way valve is available in two redundant designs:

Contact

Voith Digital Solutions GmbH
Actuators and Governors
Voithstr. 1
74564 Crailsheim, Germany

Tel. +49 7951 32-470
Fax +49 7951 32-605
turcon@voith.com

Product inquiry

Technical data

Flow rate Up to 600 l/min [158 gpm] at 1 bar [14.5 psi] differential pressure
Input pressure Up to 200 bar [2,900 psi]
MTBF (Mean Time Between Failures) 180 years (calculated in accordance to MIL‑HDBK‑217 and Siemens SN 29500, actual MTBF evaluations from installed products show even higher values)
Supply voltage 24 VDC
Current consumption 1.0 A (3.0 A for t < 1 s)
Input signal 4 – 20 mA
Communication (optional)
  • EtherNet/IP

  • Sercos

  • EtherCAT

  • VARAN

  • PROFINET

  • others on request

Fail-safe operation Internal return spring
Ambient temperature -20 to +80°C [-4 to 176°F] (standard version, not rated for use in potentially explosive areas)
Explosion proof rating (optional)
  • ATEX (II 2G IIC T4, Ta = -30...+60°C)

  • CSA C/US (Class 1, Div. 1, 2, Group B, C, D, Temp. Code T4)

  • IECEx (Ex db llC T4, Ta = -30...+60°C)

  • KOSHA (Ex db llC T4, Ta = -30...+60°C)

  • others on request

Protection class IP 65
Safety integrity level SIL 2

Advantages and benefits

  • The Mean Time Between Failures (MTBF) is over 180 years. Your equipment operates very reliably. Productivity increases and the costs associated with lost production remain low.
  • Voith way valves are not sensitive to contaminated pilot oil. Turbine lubricating oil is suitable as the operating fluid. One oil supply system for both lubricating and pilot oil suffices. Maintenance is simple, which helps you lower operating costs.
  • During load rejection, the way valve shifts the control valve to the partial-load position very rapidly (approx. 300 ms). When a shutdown command is received, the way valve shifts the control valve to the safe position (open or closed) very rapidly (approx. 300 ms). This ensures high availability of your equipment.
  • The way valve incorporates fast and exact position control. Very good control response, almost no hysteresis and a resolution better than 0.1% ensure very fast and accurate control. You benefit from having a stable process with high product quality.
  • Connections are industry-standard. The way valve mounts to your equipment easily. This reduces the costs for integration.
  • The stroke and control gain can be adjusted easily on-site by means of potenti­ometer. This allows you to adjust both quantities to the application quickly and without any delays.
  • For use in hazardous areas, we offer explosion proof way valves with the required certificates.

Typical fields of use

  • Operation of the control valve of
    • steam turbines
    • gas turbines
    • compressors
  • Retrofit of mechanic-hydraulic valve controls
  • Upgrade of systems with Voith DSG I/H converters
  • Upgrade of systems with Woodward CPC or CPC-II converters

Technical information

3/3 way valve design

3/3 Way Valve WSR – Design

 
4/3 way valve design

4/3 Way Valve – Design

A Load connection (output)
T Tank connection
P Oil supply connection (input)
1 Control magnet housing
2 Plunger
3 Potentiometers
4 Manual adjustment
5 Electrical connection
6 Hydraulic section
7 Control piston
8 Control spring
9 Rod
10 Magnet armature

 

3/3 way valve

for single-acting hydraulic cylinders

3/3 Way Valve WSR – Function

 
4/3 way valve

for double-acting hydraulic cylinders

4/3 Way Valve WSR – Function

 
On the basis of the control deviation (setpoint w – actual value x) and the control gain settings KPU and KPD, a command variable UMAG is generated for the magnetic force's controller. The magnetic force FMag is determined indirectly by measuring the magnetic flux with the aid of UHall and sent to the controller. FMag acts on the control piston in the hydraulic pilot valve via the plunger. The piston is forced against the control spring until the stroke-dependent spring force FF equals FMag. This provides a volume flow that varies in direction and magnitude, and produces stroke s in an externally mounted hydraulic cylinder. A position sensor determines the actual position and feeds an electrical signal back to the position controller. This ensures closed-loop control of hydraulic cylinder positioning.

A, B Load connections (output)
T Tank connection
P Oil supply connection (input)
X0, X1 Parameters for stroke adjustment (potentiometers)
KPU, KPD Control gain settings (potentiometers)
w Position setpoint
x Position actual value
F Force
FMag Magnetic force
FF Spring force
U Voltage
UHall Hall voltage
UMag Voltage applied to magnetic force

 

Control schematic for a 3/3 way valve

3/3 Way Valve – Control Schematic

 
Control schematic for a 4/3 way valve

4/3 Way Valve WSR – Control Schematic

Selection table for 3/3 way valves

Type Maximum 
input
pressure [bar]
Flow rate [l/min] at
1 bar differential pressure
P > A A > T
WSR-C25XXX 200 17 62
WSR-C45XXX up to 40 22 75
WSR-C60XXX up to 40 35 150
WSR-E60XXX up to 40 30 350
WSR-E80XXX up to 40 50 600
WSR-K120XXX 25 600 600

Selection table for 4/3 way valves

Type Maximum
input
pressure [bar]
Flow rate [l/min] at
1 bar differential pressure
P > A/B A/B > T
WSR-D16XXX up to 160 14 14
WSR-D24XXX 40 40 40
WSR-D45XXX up to 40 80 80
WSR-D60XXX 40 130 130
WSR-D80XXX 40 180 180
WSR-K120XXX 25 600 600

Publications



Electro-hydraulic I/H Converters and WSR Way Valves, Actuator Technology for Positioning Cylinders on Turbomachinery

Electro-hydraulic I/H Converters and WSR Way Valves, Actuator Technology for Positioning Cylinders on Turbomachinery

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