Weyerhauser Replaces Another Failed Feedwater Regulator

At their Valiant Paper Mill in Oklahoma, the Weyerhaeuser Paper Company has replaced a feedwater regulator valve serving their power boiler with a six inch (150 millimeter) CCI valve. The existing valve (Hammer Dahl) required frequent replacement of the seat due to severe erosion damage. Flow control and resolution were also problems with the existing valve. The selection of a second CCI DRAG® valve here reflects their successful experience with an exact duplicate DRAG® valve serving their heat-recovery boiler which was installed only a few months ago. Plant people were pleasantly surprised with performance of the first CCI valve, which resulted in the smoothest plant startup ever.

The new six inch (150 millimeter) feedwater regulator is specifically designed for high rangeability and good control at low flows. Its maximum design flow is 800,000 pounds/hour (36,000 kilograms/hour) at an inlet pressure of 2000 psig (130 Barg) and a DP as high as 1300 psi (90 Bar) at 400 F (204 C).

Trim exit fluid velocity is limited to 100 feet/second (30 meters/second) by incorporating 14 stages of pressure reduction in the disk stack. Good low flow control is achieved by using highly characterized disk stack and a high-resolution actuator.

The new valve will also combine functions of main and startup feedwater valves in one valve, thereby eliminating the need for transition during the startup process.

Published in SOLUTIONS Winter 2000