What are the Types of Fuel Pumps?

What is fuel pump?

The fuel pump is the key device that transfers fuel from the fuel tank to the engine. It ensures that the fuel reaches the engine at the proper pressure and flow so that the engine can function properly and provide power. Fuel pumps are used in a wide variety of vehicles and machinery, including cars, trucks, agricultural machinery and construction equipment. The types of fuel pumps and how they work vary by application and technology, from traditional mechanical pumps to modern electric pumps, fuel pumps are unique in their design and function.

 

What are the types of fuel pumps?

Low-pressure mechanical pump

Low-pressure mechanical pumps are typically used in carbureted engines, such as older cars, lawnmowers and power tools. These pumps operate at relatively low pressures, usually between 10-15 psi (0.7-1.0 bar). The most common types of low-pressure mechanical pumps include diaphragm pumps and piston pumps, which transfer fuel from the tank to the carburetor by mechanical movement. They are commonly found in older models of mechanical equipment or in application scenarios where high fuel pressure is not required.

 

High-Pressure Mechanical Pump

High-pressure mechanical pumps are used in modern direct injection engines, and these pumps can operate at pressures up to 30,000 psi (2,100 bar). Configurations of high-pressure mechanical pumps include common-rail radial piston pumps, common-rail dual-piston radial pumps, in-line pumps, ported and screw pumps, and metering units. These pumps are typically lubricated by fuel to prevent lubricant contamination of the fuel. These pumps pressurize the fuel by means of complex mechanical devices to ensure that the fuel is delivered precisely to all parts of the engine at high pressure. High-pressure mechanical pumps are widely used in modern high-performance engines for their ability to provide a consistent and precise fuel supply.

 

Port and Screw Pump

Port and screw pumps are commonly used in marine diesel engines due to their simplicity, reliability and ability to be scaled to engine size. The pump design is similar to a radial piston pump, but uses a machined plunger without seals. The amount of fuel pumped to the injectors can be controlled by rotating the plunger through a rack and pinion mechanism. The design of this pump provides the flexibility to adjust the fuel supply under varying operating conditions, thereby improving engine fuel efficiency and performance.

 

Plunger Pump

Plunger pumps are a type of positive displacement pump used in diesel engines. These pumps contain a chamber that increases and/or decreases volume by moving a plunger, and have check valves at the inlet and discharge ports. Plunger-type pumps are usually mounted on the side of the injection pump, are driven by a camshaft, and typically operate at fuel pressures between 3,600-26,100 psi (250-1,800 bar). Due to the precision of their design, piston pumps are capable of delivering extremely high fuel pressures for modern high performance machinery and equipment.

 

Electric Pump

Electric fuel pumps are widely used in fuel-injected gasoline engines and are usually located in the fuel tank. For older port injection and throttle body injection systems, this "in-tank" fuel pump delivers fuel from the tank to the engine and pressurizes the fuel to 40-60 psi (3-4 bar). For direct injection systems, an in-tank fuel pump delivers fuel to the engine and a separate fuel pump pressurizes the fuel to a higher pressure. Electric pumps require no mechanical power from the engine, so they can be flexibly placed anywhere between the engine and the fuel tank. Electric pumps are also low-noise and high-precision, making them suitable for application scenarios where precise fuel supply is required.

 

Turbopump

Turbine pumps are used in rocket engines to supply fuel and oxidizer to the combustion chamber. These pumps are designed for high pressure and high flow rates to meet the stringent requirements of rocket motors. Turbopumps typically have sophisticated mechanical and electronic control systems to ensure accurate supply of fuel and oxidizer.

 

There are many different types of fuel pumps, each with its own unique design and application scenarios. Understanding the operating principles and characteristics of different types of fuel pumps is critical to selecting the right fuel pump and ensuring the efficient operation of your mechanical equipment.