There are other posts on pumps that are more helpful. This one got pretty confused by the OP. If you call TCW equipment (Michael on this post), they are very knowledgeable, and will give you a full rundown. It depends on how much and what you are pumping (what temp, solids or liquids). As mentioned, many use a flojet G70 spirits. If you are just pumping liquids at lower temperatures I'd recommend a flexible impeller pump. Diaphragm pumps need a compressor, and are loud. If pumping hot solids, rotary lobe pumps are the best pumps I've used, but are expensive, and usually require a bit more maintenance.