Pumps for Edible Oil: Crude, Refined & Process Transfer

Centrifugal pumps use centrifugal force through the rotation of the pump impeller to draw fluid into the intake of the pump and force it through the discharge section via centrifugal force. The flow through the pump is controlled by discharge flow control valves. Single stage centrifugal pumps are primarily used for transferring low-viscosity fluids that require high flow rates.

Plunger pumps are some of the most ubiquitous industrial pumps in the oil industry. Plunger pumps use the reciprocating motion of plungers and pistons to pressurize fluid in an enclosed cylinder to a piping system. Plunger pumps are considered constant flow pumps since at a given speed, the flow rate is constant despite the system pressure. Its noisier operation than centrifugal pumps.

Progressive cavity pumps are also considered constant flow pumps since at a given speed, the flow rate is relatively constant despite the system pressure. Flow slippage is normal at higher pressures. A relief valve is an essential part of any progressive cavity pump discharge piping system to prevent over pressuring of the pump and piping system.

Diaphragm pumps are one of the most versatile types of oil pumps in the industry and transfer fluid through positive displacement with a valve and diaphragm. Diaphragm pumps are suitable for high-volume fluid transfer operations in oil refineries. They also require much less maintenance than positive displacement pumps due to their fewer moving parts and less friction during operation and are available in compact designs.

Gear pumps are positive displacement (or fixed displacement), meaning they pump a constant amount of fluid for each revolution. The internal gears do not touch, so non-lubricating fluids can be pumped with external gear pumps. Internal gear pumps use a shaft driven drive gear to drive the internal mating gear. Since the pumped fluid passes between the close gear tolerances, gear pumps are normally used for clean fluids.

A metering pump moves a precise volume of liquid in a specified time period providing an accurate flow rate. Delivery of fluids in precise adjustable flow rates is sometimes called metering. The term “metering pump” is based on the application or use rather than the exact kind of pump used. Most metering pumps are simplex reciprocating pumps with a packed plunger or diaphragm liquid end. No pumped liquid leaks to the atmosphere.