Reliability Adds Up

This facility uses four gas turbines in a one-on-one configuration with steam injection control valves in its HRSG system. By contract, the original equipment manufacturer (OEM) warranted the turbine components based on unit starts and run time. Turbine trips resulted in costly penalties per the contracted, allowable wear-and-tear on the components. Each trip costs about $140,000 USD in repairs (labor and materials) and downtime (lost MW production).

The OEM blamed a series of ten trips on two Fisher™ CV500 control valves in the steam-injection system. According to them, the valves’ slow response once steam-injection was initiated was causing the unit to trip. The OEM told plant managers that the valves on units 1 and 3 needed to be replaced immediately. The plant manager called Novaspect engineers and Emerson repair experts to verify that the valves were the problem. With two days notice, the Emerson team arrived on site to perform advanced diagnostics on both valves, which were equipped with Fisher FIELDVUE™ DVC6200 digital valve controllers.

Emerson’s on-site services and diagnostics saved the plant up to $1 million USD and improved the reliability of its steam-injection system. Though difficult to quantify, the plant increased overall mass flow through the turbine, reduced gas emissions, and improved its generating capacity.