Abstract: There were problems of sealing untightness and leakage occurred in the feed pump recirculating valve of Liaoning Huadian Tieling Power Generation Corporation Limited. The reasons found by analysis were cavitation, encroachment and attack occurred at the sealing face of the valve seat. The valve structure was reformed by adopting three measures. The sealing and adjustment performance of the reformed recirculating valve are excellent, and leakage fault des not occur again in operation. So a good economical benefit was obtained.

Key words: recirculating valve of feed pump, encroachment, cavitation, attack, analysis, structure reformation, solving method