1-inch Pressure Reducing Valve (#1500) Repair – Son Dong Power Plant

Information:

Mark One valve, 1 inch, class 1500, used as a pressure reducing valve in the boiler system of the power plant, equipped with an electric actuator with 4-20mA control signal.

Condition:
Multiple valves were supplied, but one valve experienced hunting.

MOG’s Solutions:

• Inspected on-site; hunting was observed. Adjusted deadband and hysteresis settings in the electric actuator’s menu and checked signal cable interference — no improvement in hunting;

• Ordered a new main board; the manufacturer replaced the main board and feedback encoder, but hunting persisted after some time;

• Ordered a new actuator; SVAL replaced the actuator on-site — the valve resumed normal operation.