Deltaway Develops Method for Assessing Control Valve Leaks

Deltaway Energy International, Inc., a major U.S.-based waste-to-energy (WTE) facilities design and management firm, has announced that its engineering group has developed an innovative method for estimating control valve leakage flows using very brief testing while plant systems remain online.

“Bypass valve leakage is one of the primary causes of steam loss in any power plant,” says Fred Caillard, Deltaway’s senior performance engineer. “Our test helps plant maintenance teams better balance the cost of repairs against the cost of reduced power generation.”

The noninvasive test involves measuring the time required for existing plant instrumentation to adjust to various operating conditions. The steam leakage volume is then computed using the scientific assumption that the heat exchange coefficient between steam and a thermocouple increases with steam velocity.

Deltaway’s method helps plant managers schedule the ideal timing for servicing bypass valves. The method improves on the current practice of calculating main steam flow differentials, which often results in inaccurate leakage estimates and poorly timed repairs.