The path of fuel flow through the system is pretty simple. Diesel fuel tanks normally are positioned above the engine''s fuel-injection pump to provide a positive pressure head to the fuel filter and transfer pump. This positioning assures easy priming of the system and assists fuel flow as the filters become more restricted. The fuel is moved by the transfer pump (usually a diaphragm type).The transfer pump, normally with the help of gravity, pulls the fuel through a primary filter and pushes it through a secondary filter before the fuel reaches the main pump. When a camshaft lobe in the injection pump lowers the plunger, the transfer pump pushes fuel into the chamber above the plunger in proportion to the position of the metering system. As the engine camshaft rotates, the injection pump plunger rises, pushing the fuel at high pressure out of the delivery valve, into the high-pressure fuel lines, and on to the injector nozzle. The high-pressure fuel inside the injector nozzle surrounds the valve (piston) and pushes up on the piston step against a predetermined spring setting. As the piston lifts, fuel leaves the nozzle tip and flows out the nozzle orifice into the pre-combustion chamber or cylinder.

* How important is run-out of the installed component?* What are the tolerance or precision requirements of the specific industry you are in?Keith/U.S. Tsubaki: Proper selection requires more than calculating the required torque. Centering requirements, ease of installation, and the forces the unit applies to the shaft and hub also apply.Jeff/KTR: Precisely determine the hub location required for the desired application. Evaluate the radial and axial position and the amount of space available for the locking device, and then select the type of device needed.Andrew/Whittet-Higgins: Choose the right device, taking into consideration static and dynamic loading, assembly, maintenance, misalignment, price of the full assembly, and availability.Vic/Rimtec: Avoiding keyways improves shaft maintenance. Using keyless clamping locking devices or shrink discs makes it easy to change parts.

Gas cylinders and dewars are becoming relics thanks to the advent of gas-generation systems. These generators turn compressed gas into nitrogen, and deionized water into hydrogen gas. Over the last several years, advances in technology have significantly increased use of these on-site gas generators. Membranes, specialized adsorbents and catalysts, improved air compressors, and enhanced electronic controls have fueled this wave of progress.Gas generators provide consistent, reliable, on-site supplies of gases that are instantly ready for use. And since gas generators eliminate the need to store gases, they also do away with injuries caused by lifting and dropping heavy metal cylinders. Doing away with cylinders also eliminates the costs of maintenance, shipping, returning, and storing them. There is also no need to keep hydrogen generators away from oxidizing gases or to locate generators in specially constructed areas.

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