The Details
Alstom Power – Natural Gas Valve Skids
As part of IPL Harding Street Coal-to-Gas Conversion Project, Wahlco has supplied Two Natural Gas High Pressure Reduction Skids that supply Natural Gas Fuel to both Units 5 and Unit 6. The rated fuel capacity for each is approximately 1,176,000 SCFH.
The Natural Gas Pressure Reduction Station is designed to regulate fuel gas from 200 – 350 psig down to 50 psig. The station consists of two parallel trains for main flow and low flow scenarios respectively. For the main flow train, the pressure reduction is accomplished by one pressure regulator and one globe control valve in series. The regulator reduces the pressure to a median value and the control valve provides a second stage pressure reduction. For the low flow train, two pressure regulators are installed in series to reduce the pressure in two stages.
Each of the pipe trains has a motor-operated automatic shutoff valve near the skid inlet that are opened or closed by the main control system, based on flow demand or other conditions. Instrumentation is also installed on the skid, including pressure transmitters that monitor the natural gas pressure at the station outlet, and a high pressure switch to facilitate closing the shutoff valves in an emergency.