What does a non return valve do in a fuel system?
Non-return valves are frequently used when retrofitting veteran and classic cars to prevent fuel tank and line leaks. Installation examples can be found in the text.
Why do diesels have return lines?
It is used as a lube in a diesel engine, and does not get burned in the chamber. This leftover oil is sent back to the tank.
Do I need a check valve in my fuel system?
According to the FUELAB folks, the idea of a check valve is to hold fuel rail pressure, lower the fuel system’s priming time, and help with hot starts. Maintaining the pressure during engine cooling helps to prevent vaporizing of the fuel in the rail, which reduces evaporative emissions.
Do you need a non-return valve?
Non-return valves are used in systems where it is desirable to make sure fluids flow mostly in one direction, but may not be critical, for example in pumped systems such as heating circuits.
How much pressure is in a diesel return line?
You don’t need the check valve but the pressure where the injector return line connects back into the system needs to at lift pump output pressure, about 18-35 psi.
Are diesel fuel tanks pressurized?
The function of the diesel fuel system is to inject a precise amount of atomized and pressurized fuel into each engine cylinder at the proper time. Combustion in a diesel engine occurs when this rush of fuel is mixed with hot compressed air. (No electrical spark is used in a gasoline engine.)
What is the purpose of a fuel return line?
It is also used to connect the fuel return line (banjo fitting) to the fuel injection pump. Fuel volume from the fuel transfer (lift) pump will always provide more fuel than the fuel injection pump requires. The overflow valve (a check valve) is used to route excess fuel through the fuel return line and back to the fuel tank.
What is a one way valve on a diesel engine?
Darwen Diesels stock a range of Non return or one way valves varying from 6mm – 13mm. One way valves can be used for a multitude of problems, mainly where the fuel has drained back to the fuel tank due to the system drawing in air overnight. This has been a problem for many years.
How is excess fuel returned to the fuel tank?
Fuel volume from the fuel transfer (lift) pump will always provide more fuel than the fuel injection pump requires. The overflow valve (a check valve) is used to route excess fuel through the fuel return line and back to the fuel tank. Approximately 70% of supplied fuel is returned to the fuel tank. The valve opens at approximately 97 kPa (14 psi).
Where is the pressure relief valve on a fuel injection pump?
The overflow valve (pressure relief valve) is located at the outside of fuel injection pump. It connects the fuel return line (banjo fitting) to the pump. The valve has no internal serviceable parts and must be replaced as an assembly. Two sealing gaskets are used. One gasket is located between pump and banjo fitting.
https://www.youtube.com/watch?v=iiLW5KQNIEM