Two are Better Than One at PLN

For PLN’s Paiton drum boiler plant in Indonesia , just one CCI replacement valve is good – but two are even better!

The Paiton plant had a Fisher 5”x5” angle body modulating valve that was experiencing serious problems with erosion because the valve was taking a high pressure drop of 248 bar in only two to three stages. This number of stages was insufficient to reduce the trim exit velocity and thus led to cavitation problems. The result was continuous leakage through the valve that decreased pump efficiency. Cavitation and vibration also caused production losses and reduced the unit’s performance. In addition, the diaphragm supplied with the Fisher valve did not have enough seat load to provide tight shutoff.

The BFP recirculation valve is one of the most critical severe service applications in a power plant. The key to this valve’s success is a sufficient number of pressure-reducing stages to limit the trim exit velocity and a high seat load of 1,000 PLI to ensure high thrust from the actuator. Because this valve is closed most of the time, it is also important that there is no wire drawing through the plug and the seat. The high seat load, combined with velocity control through the disk stack, eliminates any trim erosion and the possibility of wire drawing.

To meet these standards, CCI designed a DRAG® BFP recirculation valve featuring super-tight MSS-SP-61 shutoff and 24 stages of velocity reduction that dropped the trim exit velocity to 23 meters per second. The combination of velocity control and leak-tight shutoff prevents trim and body erosion as well as valve leakage to improve efficiency.

Those at PLN were impressed with CCI’s solution and the attention CCI paid to the plant’s overall problem; in fact, the customer was so pleased with the service it received that it decided to purchase two of CCI’s BFP recirculation valves. The first valve has been delivered to and commissioned at the site, and since installation, the valve has achieved zero leakage and has eliminated the plant’s severe service valve troubles.

Through working with CCI, the customer learned that its old, leaky valve had been costing the company more than just annual maintenance; the actual cost of the problem equated to substantial losses in overall efficiency. But with its new DRAG® recirculation valves, the plant is expected to save roughly $58,000 per year!

Published in SOLUTIONS Spring 2004