Compared with centrifugal pumps
In terms of flow stability: The flow rate of a centrifugal pump changes significantly with variations in pressure. However, the rotary piston pump is a constant-flow pump, and its flow rate is independent of the head. At a certain rotational speed, the flow rate remains constant, enabling it to provide a stable flow output. It is more suitable for petroleum transportation and processing processes that have high requirements for flow stability.
In terms of self-priming ability: Generally, centrifugal pumps do not have the ability to dry-suction and are highly sensitive to air intake. In contrast, the rotary piston pump has excellent self-priming functionality and can automatically suck in petroleum at startup without the need for external auxiliary devices. It is especially applicable for extracting petroleum from low-level containers such as underground oil tanks or oil ponds.
In terms of pressure and efficiency: When a centrifugal pump is used to transport high-viscosity petroleum, the friction between the impeller and the viscous fluid increases, resulting in a reduction in efficiency. To maintain a relatively good efficiency, its displacement and head need to be reduced. The rotary piston pump maintains a stable efficiency when transporting high-viscosity media and can still achieve high efficiency under high-pressure conditions, and it can easily reach a relatively high pressure.
In terms of structure and maintenance: Rotary piston pumps with the same flow rate are much smaller in size than centrifugal pumps, are lightweight, and are convenient to install and use. Moreover, they have a simple structure, are easy to manufacture and process, are inexpensive, and have relatively low maintenance costs.
Compared with gear pumps
In terms of flow and pressure stability: Gear pumps have problems such as unbalanced radial forces and large flow pulsations. In contrast, the rotary piston pump has a continuous and pulsation-free flow and can provide relatively stable flow and pressure outputs, reducing fluctuations during the transportation process.
In terms of self-priming ability: Although gear pumps also have a certain degree of self-priming ability, the self-priming ability of the rotary piston pump is stronger and can adapt to more complex suction conditions.
In terms of sealing and maintenance: Gear pumps have relatively large leakage, and the leakage at the end face clearance accounts for 80% - 85% of the total leakage, resulting in a low volumetric efficiency. The rotary piston pump adopts effective sealing structures and sealing materials, which can better prevent petroleum leakage, reduce the risk of environmental pollution, and at the same time ensure the working efficiency and safety of the pump. In addition, the interchangeability of gear pump parts is poor, and it is not easy to repair them after wear. The rotary piston pump has a relatively simple structure and is more convenient to repair.
Compared with screw pumps
In terms of flow stability: When a screw pump is used to transport high-viscosity media, if the viscosity of the media changes significantly, the flow may become unstable. The flow stability of the rotary piston pump is not affected by the viscosity of the media and can always maintain a stable flow output.
In terms of self-priming ability: The self-priming ability of the rotary piston pump is usually stronger than that of the screw pump, and it can suck in petroleum and establish a stable transportation pressure in a shorter time.
In terms of shear force: The screw pump has a relatively large shearing effect on the medium during the transportation process, which may have a certain impact on the molecular structure and performance of petroleum. The rotary piston pump has a relatively small shearing effect on petroleum, can reduce the impact on the molecular structure and performance of petroleum, and is suitable for transporting petroleum products that are sensitive to shear.
Compared with reciprocating pumps
In terms of flow stability: The flow and pressure of reciprocating pumps have relatively large pulsations. Especially for single-acting pumps, the pulsations are even greater. The rotary piston pump has a continuous and pulsation-free flow and can provide a stable flow output, and it is more suitable for occasions with high requirements for flow stability.
In terms of operating efficiency: During the operation of reciprocating pumps, due to the acceleration of piston movement and the intermittence of liquid discharge, the efficiency will be affected to some extent. The rotary piston pump has a relatively high efficiency, and its energy-saving effect is very significant in the case of small and medium power. Its efficiency is stable and does not fluctuate with changes in the head.
In terms of structure and maintenance: Reciprocating pumps have a low speed, are large in size, have a relatively complex structure, require special pump valves, and have relatively high manufacturing costs and installation expenses. The rotary piston pump has a simple structure, is small in size, is lightweight, is convenient to install and use, is easy to manufacture and process, and is inexpensive.
