Plastic Siphon Pumps For light duty pumping of water-based fluids, light oils, soaps and liquid waxes, inexpensive and easy to use all polyethylene siphon pumps are an excellent choice. Pump the bellows to prime the pump and begin the siphoning action from a higher to lower level, or continue to pump and begin the siphoning action from a higher to lower level, or continue to pump the bellows to dispenses fluids to a higher level. To stop the flow, simply loosen the vent cap. The standard siphon pump siphons five gallons per minute, while the heavy-duty design pumps seven gallons per minute and provides a longer life when pumping aggressive chemicals. Both pumps feature a bung adapter that fits all containers with 2" IPS female threads.