Air Leak Detection Solves Actuator Malfunction

When an East Texas Power Plant’s header system of injection water to the bottom ash sumps continued to operate well below the optimum level, plant reliability was called on. At first opportunity, the double-acting, air actuated, high-performance butterfly valves installed on the header were inspected.

In test performances, some of the valves would open or close completely, but the greater percentage of valves were found to only partially open or close. The seemingly obvious answer was undersized or faulty actuators.

Advanced Industries staff were contacted to inspect the products and help provide a solution. In a field inspection, AI staff confirmed that the actuators were purposely a bit oversized based on valve seating, unseating torque values and the high-stress nature of the application. The actuator should not be the problem.

Still, without a customer solution, AI staff began to ask questions about air supply. Theoretically, the plant air compressors were delivering 20psi greater than that required to actuate properly.

With the help of AI staff and the FLUKE ii900 Sonic Industrial Leak Detection Imager, the air piping system was inspected from the air compressors to the delivery of plant air to the valve actuators.

Plant personnel was amazed at the number of leaks detected throughout the air piping systems. Due to the leaks, the result at the delivery point was 15-30 psi below that required to properly operate the actuators.

Once the leaks were repaired, the problem was resolved.