BACK TO PROJECTS INDEX Gas Fired Power Plant After a successful start up and operation of this 240 MW gas fired power plant, Mohlin & Company was asked to assist in improving several operational issues. An existing Ammonia Injection System, part of their SCR emission control system, did not have a back up. If the existing fan pump were to go down, the entire plant would have to shut down because they would not meet their state's emission standards. Mohlin & Company designed a new back up system which included installation of a new ammonia injection fan pump, ductwork and expansion joints to allow a by-pass of the existing system and continuous operation of their emission control system in the event of a loss of their existing fan. During periods when gas supply pressure falls below 500 PSI, the existing facility is equipped with a compressor which increases the pressure of the incoming gas to acceptable pressures. When the compressor is activated, however, the existing gas lines appear to have excessive vibration. Mohlin & Company provided a pipe stress analysis and designed additional pipe supports at appropriate locations to reduce the vibration. At the same time a new 600 PSI pressure reducing valve (PRV) and associated piping was added to help control the pressure in the incoming gas line. In addition to the design, Mohlin & Company provided assistance during the shutdown to help insure proper installation.