Unlike a centrifugal pump, a rotary pump is self-priming and works through the principle of positive displacement. This simply means that whenever the pump makes a complete revolution, a fixed volume of water is moved, despite the resistance pushed by the pump. The only risk here is that any blockage in the system can easily cause a rapture or damage to the pump. The pump operator therefore needs to ensure that the system is properly aligned to create a complete flow path. The pump requires a relief valve to protect the piping system. It lifts at certain pressure and returns the fluid back to the pump or to the suction side of the pump.
For most types of pumps, the pump is located below the liquid so that gravity can create a static pressure to keep the pump primed. Rotary pumps operate a bit differently because the pump is above the fluid. They use a similar principle to that of a drinking straw to generate the force that pulls the fluid up.
How it works
When you start the rotary pump, air is quickly pumped through the side of the pump, creating a low pressure area at the sanction side. Atmospheric pressure naturally forces the liquid up the pump. This means the pipe between the pump and the liquid must not leak because that would totally interfere with the working mechanism. The prime is naturally sustained when the piping begins.
Global Vac is a dedicated supplier of GPR series rotary pumps useful for a wide range of research, laboratory, processing, vacuum drying, laser thermoforming and electronic assembly applications