Electro-hydraulic actuator

ISA 5.1-2009/2022 (final control element actuators) / PIP PIC001

Drawn as

A rectangle on the valve stem marked "EH".

Meaning

Self-contained actuator with its own electric pump and hydraulic cylinder. Used for remote, large or subsea-tie-in valves where there is no air. ESD duty makes it an esd-valve in the model.

Variants

Some legends draw a hydraulic cylinder with an M beside it