A Leading Chemical Company - #50 Vent Header Control Valve
Improve 50# Steam Header Control
The customer had parallel Masoneilan Cam Flex valves installed on their 50# steam header system. The valves were selected to operate on a 20/80 ratio to prevent over-pressuring their 50# steam header and lifting safety relief valves. The valves offered poor control in part because the control strategy was not set up to transition the smaller valve closed before opening the larger valve, which caused the larger valve to operate very close to its seat. They also leaked steam, but the amount could not be quantified.
During an outage in late 2011, the customer removed the two Cam Flex valves and installed a single Fisher V150. They also modified the control strategy and implemented a single PID control. The simplified control strategy and single valve solution has been operating fine for nearly a year with good results. There was an existing vent silencer associated with this solution that has never properly attenuated the noise so they are planning to replace that with a PULSCO solution that was engineered to operate with the V150 valve.
The valve replacement has resulted in savings of $30,000 annually in reduced steam leakage and maintenance.