The purpose of the Michigan Custom Machines fuel injector nozzle test machine is to test a fuel injector nozzle assembly for mass flow, valve opening pressure (VOP) and leakage. Depending on the fuel system, the nozzle assembly could be a subassembly of the fuel injector an aerospace fuel nozzle or in some cases, the complete injector. Typical calibration fluid is Viscor 1487 (ISO 4113), C3112 type II, Skydrol or other calibration fluids.
Injector Nozzle Description
A typical diesel injector nozzle is typically made up of a nozzle tip, a check, spring, spacer plate, stop pin, sleeve and case. Different manufacturers may use slightly different terminology, but the basic components are all there. Direct injection systems couple the pump directly to this assembly which would then make it the injector. Other systems take the nozzle group and attach it to another mechanism that or valve that make up the remainder of the fuel injector. When high pressure fuel enters the nozzle, it travels down through the sleeve to the area where the check seals the delivery orifices in the tip. The check is biased closed with a spring. As the pressure to the check increases, the force overcomes the spring and causes the check to lift, allowing fuel to exit through the orifices. Our machine measures the precise pressure point at which the check lifts. This is called Valve Opening Pressure (VOP). Once the check is open, it will remain open as long as the supply pressure remains above the VOP. During this time our machine also measures that mass flow rate through the nozzle. When the supply pressure drops below VOP, the check is forced closed by the internal spring to seal the nozzle tip orifices. Our machine also performs a leak tests to verify that this interface is working correctly. We call it a “tip leak” test. Lastly the machine checks for guide leakage in the nozzle group, which is the interface between all of the fuel delivery passages within the nozzle.
Click on image below for full data sheet or contact us at 248-347-7900 for more information. You can also view some of the other custom Fuel System Testing Machines we’ve built for other customers.