Commonly called rotary vane pumps, they have a built-in bypass relief valve to prevent pressure buildup. Attach an electric motor with a speed reducer or a belt pulley to alter the pump speed. Use a NEMA 56C frame motor. Pumps are gravity fed and require an elevated liquid source to fully fill the pump before turning on. Do not run dry or use with solids. They meet NSF/ANSI 61 safety standards for use with drinking water systems.

Pumps with a 303 stainless steel housing are more corrosion resistant than pumps with a brass housing.

Commonly called rotary vane pumps, these are designed to pump water at high pressures in low-flow applications. Motor is open dripproof (ODP) for use in clean, dry, and well-ventilated environments. They have a built-in bypass relief valve to prevent pressure buildup. Pumps are gravity fed and require an elevated liquid source to fully fill the pump before turning on. Do not run dry or use with solids.

Note: If flow control is needed, place valves or reducers on the discharge side; never restrict the inlet of a pump with a valve or reducer.

Since these pumps don't require lubrication, there’s no risk of oil contamination. Maximum flow rate is the rate at which air is pumped before a vacuum is created. Flow rate steadily decreases as the pump generates the vacuum. The larger the tank, the longer it will take to form a vacuum.

Style B pumps are often used for aeration, leak detection, and liquid-level control.