Scotch Yoke (MSS)

Size: Torque of 5K to 800K in-lbf
Operating Temperature: -13°F to 158°F (-25°C to 70°C)

Design Standard

The MS Series Electro-Hydraulic actuator by PDC LLC is the ideal product for any general service on/off application, with fail safe options available, if desired. Consisting of a self-contained, bi-directional motor driven pump with an integral hydraulic cylinder and mechanical drive modules.

The MS Electro-Hydraulic’s modular design allows you to choose the best combination for your service conditions. Consisting of a mechanical drive, a control box with a choice of optional Feedback and optional Fail-Safe configuration if desired.

The actuator assembly is installed on the driven device, while the control box can be attached to the actuator assembly or remotely. Connections are then made with cables. The control box offers local command of the driven device as well as from a remote location.

As a full-featured, self-contained actuator the general service MS Electro-Hydraulic actuator supplies various input and output capabilities which include:

Inputs

  1. Remote – two contact input; open/close with intermediate positioning
  2. Local – open/close/stop push buttons stroke control

Outputs

  1. Limit Switches – mechanical; end-of-travel only
  2. Alarm Relay – signifies when the unit is unable to follow the control signal
  3. Position Transmitter – 4 to 20 mA (Optional)

Specifications

Size Range:
Torque of 5K to 800K in-lbf
Temperature:
-13°F to 158°F (-25°C to 70°C)
Supply Voltage:
208/220/240/380/400/415/440/480V, 3Ph, 50/60Hz
Motor:
1 Horsepower to 4 Horsepower
Enclosure:
NEMA 4, 4X or explosion proof
Service:
Open/Close, Fail Safe (Optional)

Design Features

  • Electrically Powered Self-Contained Hydraulic Actuator
  • Can be mounted in any orientation
  • Optional Spring Fail Safe
  • Optional Accumulator Fail Safe
  • Closed Circuit Hydraulic System
  • Linear Series
  • Rack and Pinion Series
  • Scotch Yoke Series
  • Optional 4 to 20 mA Valve Position Feedback
  • Modular Design
  • Vibration Resistance
  • Discrete Operation: Motor and pump only run when motion is needed
  • Optional ability to open or close the valves multiple times when the main power supply is lost
  • Actuators can also be provided that can open or close the valves multiple times even if the main power supply is lost.

Applications

  • Oil and Gas Pipeline Valves
  • Tank Farm Pipeline Valves
  • Chemical Pipeline Valves
  • Power Plant Pipeline Valves
  • Metallurgical Process Pipeline Valves
  • Sludge Line to Filter Press
  • Influent Valve
  • Backwash Valves
  • Altitude Valve

Chart or Graph

MSS Scotch Yoke Cylinder Series Actuator

Nominal TorqueHydraulic Closing Torque (in-lbf)Stroke Speed (90°/sec @ 50HZ)
Start (0°)Mid (45°)End (90°)DEFG
5K5,2323,0785,2325NANANA
10K10,4656,15610,4655NANANA
20K21,92312,89621,923128NANA
50K52,79131,05352,791261786
100K107,06262,977107,06245281310
200K212,106124,768212,106NA602821
400K462,823272,149462,823NANA5742
800K850,777500,457850,777NANANA77

MSS Scotch Yoke Cylinder Series Actuator with Optional Spring Fail Safe (F.S.) function

Nominal TorqueHydraulic Closing Torque (in-lbf)Hydraulic Opening Torque (in-lbf)Spring Emergency Shuthown Torque (in-lbf)Power Module Stroke Speed (90°/sec @ 50HZ)
Start
(90°)
Run
(45°)
End
(0°)
Start
(0°)
Run
(45°)
End
(90°)
Start
(90°)
Run
(45°)
End
(0°)
DEFGF.S.
5K8,3494,1715,8335,0782,1982,3955,7812,5132,7626NANANA<1
10K13,8136,8699,5418,6573,7524,0999,5144,0884,3876NANANA<1
20K31,81815,94322,38819,9618,7839,90221,7419,46010,425138NANA<1
50K68,62834,89049,99941,67818,67221,80746,72520,91024,370271786<1
100K125,53662,52087,03278,44134,06237,37086,41537,24340,21045281410<1
200K277,945132,469172,541186,12776,41973,696194,72077,34068,235NA612921<1