"Premature Modulation "

Is your rotary screw giving you the performance that the manufacturer said it would?

An area of savings in compressed air that is not usually addressed by the compressor manufacturer is that of compressor performance. Rotary screw compressors in particular are divided into two categories which are Modulating type and Load No Load type. Impact RM and it's umbrella group of independent consultants have tested over 1200 Rotary screw "modulating type compressors" and have discovered a startling statistic. We found that in 80% of the compressors tested the small valve that controls the butterfly modulation or the inlet throttle is not functioning properly. Malfunctioning or improper adjustment to these inlet controls means the compressors deliver less air than normal rating. It was not surprising to see some compressors operating at 60% of their rated capacity. In order to get a firm handle on this problem, one has to test the compressor at different pressures in order to obtain a "performance print." Testing for a "performance print" will reveal at what pressure the throttle valve begins to close prematurely. Once the unit is isolated from service the test may take 20 -30 minutes with an Impact RM multi orifice LP meter. Impact RM service can conduct this type of testing for its clients with detailed reports indicating true compressor performance in FAD (free air delivery) vs manufacturers rated capacity and CFM produced per break horsepower.