Kecol Pumping Systems supply the full range of Sandpiper double diaphragm pumps and spares. Informed customers select AODD Pumps vs other pump types when challenged with difficult pumping situations.  AODD Pumps are air (or natural gas) operated displacement type pumps which uniquely differ from all other positive displacement pumps.  As a result of air pressure acting on the entire surface of the diaphragm, the diaphragm is in a balanced condition while pumping.  This measurably extends diaphragm life over that of mechanically operated diaphragm pumps.