Pneumatic actuators

MHD micro scotch yoke

The compact member of the Susin scotch yoke family, for on/off and control of double offset butterfly valves. Symmetric or canted yoke, double acting or spring return: 12 models from 63 – 1,474 Nm.

Models: 12
Torque: 63 – 1,474 Nm
Air supply: 3.7 – 10 bar
Temperature: −20 to +80 °C
Mounting: ISO 5211 F07 / F10
Protection: IP66

View all 12 models Get a quote

About Susin Download catalogue (PDF)

How a scotch yoke works

Air drives the pistons The pin turns the yoke

Configurations

Pick a yoke and action

Four configurations, each in three sizes (01-12, 01-15, 01-17). Each one opens the model table filtered to it.

ISD3 models

Symmetric, double acting

Highest torque at both ends of the stroke; air opens and closes.

198 – 1,338 Nmair 2.8–7 bar

01-1201-1501-17

ISR3 models

Symmetric, spring return

Air drives one way, springs return the valve to its safe position.

63 – 1,014 Nmair 4.2–7 bar

01-1201-1501-17

ICD3 models

Canted, double acting

Highest torque at the open or the close end, where the valve needs it.

198 – 1,474 Nmair 2.8–7 bar

01-1201-1501-17

ICR3 models

Canted, spring return

Canted yoke with spring return, fail-close or fail-open.

123 – 1,166 Nmair 4.2–7 bar

01-1201-1501-17

Exploded view of the MHD Micro scotch yoke actuator

Built to be serviced

Ductile iron centre body. Piston and end covers in ductile iron; cylinders in stainless (Micro SS) or carbon steel (Micro CS).
Roller and pin drive. Heat-treated roller and pin transfer piston force to the yoke by rolling, for less friction.
PTFE bushings. Support every moving part and keep side load off the valve stem packing.
Modular. Converts between double acting and spring return; springs load and unload with tie rods, no special tools.

FAQ

MHD actuator questions

Symmetric (IS) or canted (IC) yoke?

A symmetric yoke gives its highest torque at both ends of the 90° stroke. A canted yoke gives its highest torque at either the open or the close end, which suits valves that need most torque at one end.

Double acting or spring return?

Double acting models (ISD, ICD) use air to open and close. Spring return models (ISR, ICR) use air one way and springs the other, so the valve goes to a safe position if air is lost. The design is modular, so one can be converted to the other.

What is the difference between Micro SS and Micro CS?

Both have a ductile iron centre body. Micro SS has stainless steel cylinders, Micro CS has carbon steel cylinders.

Can I adjust the travel?

Yes. Stopper bolts at both cylinder ends set the open and close positions between 85° and 95°.

Which accessories can be fitted?

A manual handwheel (jackscrew), hydraulic override, limit switches, solenoid valves and positioners.

Know the model?

Compare all 12 MHD models by yoke, action and torque, or send us the valve torque and air pressure and we’ll pick the size.

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