Positive Displacement Pumps: 10 Things You Should Know Before Buying
If your business is in the market for a positive displacement pump, there are several key features and facts to know before buying. Here are 10 things to keep in mind as you begin your search:
- There are two types: the reciprocating and the rotary type. The reciprocating type relies on a piston or diaphragm to generate energy through a back and forth motion. The rotary design relies on a rotational gears or blades to generate kinetic rotational energy.
- Best used if the intended application requires a constant flow rate.
- Positive displacement pumps require a minimum pressure level at the input
- If your intended application uses a high flow rate, the rotary version is not the best choice due to the rotary mechanism being worn down and losing efficiency
- Positive displacement pumps work best with high viscosity fluids, such as oils, paints, or resins.
- Unlike centrifugal valves, positive displacement pumps cannot operate with closed valves, since they cannot be shut off and could potentially cause a leaking or burst pipe
- These pumps are not self priming
- A pulsing discharge can occur with positive displacement pumps, and can create noise in the pipes. This can be mitigated through the use of additional pump cylinders and even dampeners
- Very effective for accurate dosing applications
- Produces the same flow speed no matter the discharge pressure