Pumps can typically categorized into one of three broad categories (as per wikipedia):

• Positive displacement pumps use a mechanism to repeatedly expand a cavity, allow gases to flow in from the chamber, seal off the cavity, and exhaust it to the atmosphere.
• Momentum transfer pumps, also called molecular pumps, use high speed jets of dense fluid or high speed rotating blades to knock gas molecules out of the chamber.
• Entrapment pumps capture gases in a solid or adsorbed state. This includes cryopumps, getters, and ion pumps.

Regardless of the type of pump that you need, United Vacuum stocks many new, used and refurbished vacuum pumps. Whether you need a rotary vacuum, a rotary piston pump, a rotary lobe booster, rotary vane pump or a small vacuum pump United Vacuum can provide what you’re looking for. United Vacuum specializes in the manufacturing vacuum pumps, and remanufacturing of industrial rotary piston pumps and rotary lobe blowers. Whether you require a new or remanufactured pump, United Vacuum is positioned to accommodate your needs. United Vacuum also offers comprehensive vacuum pump repair and pump remanufacturing services when purchasing a new pump is not an option.