Pipeline transfer of crude oil in refineries and terminals: which pump type is most commonly used for general crude service?

Introduction:
Refinery and pipeline operations move large volumes of crude and intermediate streams continuously. The pump choice must balance efficiency, reliability, NPSH requirements, and suitability across a range of viscosities and temperatures encountered in crude service.

Given Data / Assumptions:

• Service: continuous transfer of crude oil (broad viscosity range).
• Large flow rates with moderate heads.
• Industry standard equipment considerations.

Concept / Approach:
Centrifugal pumps dominate refinery liquid transfer due to their simplicity, wide capacity range, and ability to handle modest solids and gas entrainment with appropriate design. Positive displacement pumps (gear, screw, reciprocating) are favored for very viscous fluids, precise metering, or very high pressures at low flow but are less common for main crude transfer lines where high capacity is required.

Step-by-Step Solution:
Identify duty: high-throughput crude transfer.Select pump with high capacity and acceptable NPSH: centrifugal.Confirm: PD pumps are niche for very viscous/heavy or metering duties.

Verification / Alternative check:
Refinery P&IDs and pipeline stations show multistage or single-stage centrifugal pumps for trunk service; screw/gear pumps appear in heavy oil loading, slop service, or lube units.

Why Other Options Are Wrong:

• Gear/screw: suited to viscous services and precise flows, not typical mainline crude duties.
• Reciprocating: high pressure at low flow; less common for large crude transfer.

Common Pitfalls:
Overlooking NPSH and suction piping design; even with centrifugal pumps, poor suction conditions can cause cavitation in hot or gassy crude service.

Final Answer:
Centrifugal pump