Instantaneous flow rate is pulsating
This is because in a plunger pump, the suction and discharge processes of the liquid medium alternate, and the piston's velocity changes continuously during displacement. In a pump with only one working chamber, the instantaneous flow rate not only varies with time but is also discontinuous. As the number of working chambers increases, the pulsation amplitude of the instantaneous flow rate decreases, even to the point of being practically considered turbulent.
Average flow rate is constant
Theoretically, the pump's flow rate depends only on the pump's main structural parameters: n (reciprocating strokes per minute), S (piston stroke), D (piston diameter), and Z (number of pistons), and is independent of the discharge pressure and the physical and chemical properties of the pumped medium, such as temperature and viscosity. Therefore, the pump's flow rate is constant.
Pump pressure depends on pipeline characteristics
The discharge pressure of a plunger pump cannot be limited by the pump itself but depends on the pipeline characteristics of the pump system and is independent of the flow rate. In other words, if the pumped liquid is considered incompressible, then theoretically, the discharge pressure of a reciprocating pump can be considered unrestricted, meaning any desired discharge pressure can be established based on the pipeline characteristics of the pump system. Of course, all reciprocating pumps have a specified discharge pressure. This doesn't mean the discharge pressure can't be increased, but rather that due to limitations in the prime mover's rated power and the pump's structural strength, operation beyond this discharge pressure is not permitted.
Strong adaptability to transported media
Plunger pumps can, in principle, transport any medium, almost unaffected by its physical and chemical properties. However, limitations in the materials and manufacturing processes of the hydraulic end, as well as sealing technology, may sometimes lead to unsuitability.
Good self-priming performance
Plunger pumps not only have good suction performance but also excellent self-priming performance. Therefore, most reciprocating pumps typically do not require priming before startup. High machine efficiency and energy saving.
