Pulsafeeder CHEM-TECH Series 100/150 chemical metering pumps are positive displacement, diaphragm type pumps. Output volume is adjustable while pumps are in operation from zero to maximum capacity. The CHEM-TECH Series 100 is the standard by which all other dosing pumps are judged. CHEM-TECH Series 100/150 pumps with motorized-diaphragm technology deliver dependable performance and extended longevity. The Series 100/150 provides quiet, consistent metering over long periods of time in a compact form.