Is it possible to connect the inlet of the high-pressure reciprocating pump at a point 50 meters away from the outlet of the centrifugal pump, also on the ground level?

What is the flow rate pulsation of your reciprocating pump?

The flow rate is quite high; it keeps fluctuating within the range. There are accumulators at both the inlet and outlet, but they don’t help either. The pressure at the exit of the high-pressure pump is 8 MPa, while it’s 0.4 MPa at the exit of the centrifugal pump

Centrifugal pumps deliver material continuously, which means they pump for a while and then stop pumping. It is not recommended to connect it directly; add a buffer tank in front of the reciprocating pump

This centrifugal pump has three outlets; the other two are connected in series and handle 60% of the total flow rate, while the intermittent outlet handles 40%. It’s not clear whether operating under such conditions will cause damage to either the centrifugal pump or the reciprocating pump

I’m not sure what the total flow rate is, but the outlet pressure of your centrifugal pump under operating conditions is low; therefore, it should have little impact during normal operation. However, if the reciprocating pump stops suddenly, it will have an effect on the outlet pressure of the centrifugal pump； If the centrifugal pump stops suddenly, the inlet of the reciprocating pump will become evacuated. It would be better if there is a closed station control system. With a buffer tank, these problems don’t occur.

For the technical upgrade project, there is no space left for buffer tanks. What is a closed station?

A closed transfer process refers to a connection method in which all intermediate pumping stations on a long-distance pipeline operate in a closed manner. All the oil coming from the previous pumping station is fed into the transfer pumps at this station; there are no oil tanks connected to the atmosphere for buffering purposes at the intermediate pumping stations. The oil is transported throughout the entire system in a sealed condition, which simplifies the process, reduces the need for equipment, and eliminates evaporation losses associated with auxiliary oil tanks. All the intermediate pumping stations along the line form a unified hydraulic system; the pressures at these stations can be adjusted relative to one another, which reduces energy losses associated with regulation and facilitates automatic control across the entire line. However, a failure in any intermediate pumping station will immediately affect the operation of the entire system; therefore, the equipment, communication, and automation systems must be sensitive and reliable

That friend from the marine industry is right; if a centrifugal pump has multiple outlets, it is necessary to verify the following: 1. When both positive displacement pumps and centrifugal pumps are operating properly, the flow rates should be matched, with the supply volume being slightly higher than the demand. It is recommended to use valves to control each of the centrifugal pump’s outlets separately. 2. The centrifugal pump is operating normally while the positive displacement pump has stopped; is it necessary to shut down the centrifugal pump or take other measures to ensure that it is not affected? 3. When the positive displacement pump is running and the centrifugal pump suddenly stops, what measures should be taken to ensure that the positive displacement pump is not damaged? 4. In the above situations, is it necessary to install alarm or automatic (delayed) shutdown protection, if operation is not continuous?

What medium is being used? Why is a reciprocating pump connected after the centrifugal pump? Is it because the head is insufficient? If the head is insufficient, one should actually consider using a multi-stage centrifugal pump. The flow rate of centrifugal pumps is prone to fluctuations, and connecting a reciprocating pump directly after it poses certain risks.