Schreiber incorporates the Archimedean Screw Pump concept in both the Open Flight Screw Pump, and the Tube Mounted Screw Pump (available in variable angle and stationary angle). The Archimedes Screw concept provides variable capacity at a constant speed up to its design maximum. The Open Flight Screw Pump utilizes a concrete trough to transport liquid. The Tube Mounted Screw Pump with its simplified design, transports liquid inside a stationary tube, eliminating the need for grouting. Tube pumps can be set at a fixed angle or the lower end can be supported by a hoist to vary the pump angle to change the pumping rate or for maintenance access. Schreiber’s gravity lubrication system provides simple, reliable operation without elaborate pressurized grease systems and their inherent operational concerns. To resist corrosion, Schreiber screw pumps are hot-dipped, galvanized steel or epoxy coated, after fabrication.