Actuator and Positioner Maintenance (ACV04)

This four individual lesson program trains participants in the function, operation, maintenance, and troubleshooting of common types of control valves.

Prerequisites

This lesson is designed for participants familiar with industrial process control, specifically single loop control and multiple loop control, as well as control valve body types and trim, and the operating characteristics of positioners and actuators. A working knowledge of fluid flow characteristics and the other elements in process loops is recommended.

Description

This lesson introduces participants to causes and symptoms of actuator and positioner malfunctions and applies the concepts and terminology of actuators and positioners to the disassembly, repair, parts replacement and re-assembly of diaphragm and piston actuators.

Objectives

List common symptoms of a failed diaphragm actuator. List the causes of a diaphragm actuator failure. List maintenance requirements for a diaphragm actuator. Remove and inspect the stem and diaphragm assembly and the range spring and seal bushing on a diaphragm actuator. Replace the gasket and O-ring on a diaphragm actuator. List common symptoms of a failed piston actuator. List the causes of piston actuator failure. List maintenance requirements for a piston actuator. Remove pneumatic and electro-pneumatic positioners and the causes of failure. List maintenance requirements for a pneumatic positioner. Inspect and clean the pilot relay assembly on a pneumatic positioner. List the causes of i/p transducer failure on an electro-pneumatic positioner. Adjust the zero and span on an electro-pneumatic positioner.