Engineers at Flowserve Corp., Irving, Tex. (, are ready with the Guardian 3000 pump. Its outside diameter of 1.42 in. and a length of 3.54 in. makes it the smallest pump the company has ever made. The small size lets it fit in the tight confines of PC enclosures. The pump uses an overhung centrifugal, nonmetallic drive and is powered by a 12-V brushless-dc motor.