Baldor GLC125, GLC35, GLC80, GLC50 Garretson Model KN Fuel Valve Considerations General, Service

Garretson Model KN Fuel Valve Considerations

General

The KN is designed for sensitivity and simple operation. It is used with low–pressure vaporized gaseous fuels, where dependable starting is a requirement. Because of its extreme sensitivity, the KN offers excellent results in most remote starting applications (Standby power generators, etc.). With proper installation and maintenance, the KN will provide years of trouble–free service.

Operation

The KN is an atmospheric zero governor which acts like the float and needle valve in a gasoline carburetor. Air–flow through a venturi in the carburetor creates a vacuum, which acts through the outlet of the KN on the diaphragm. Atmospheric pressure then forces the diaphragm toward the vacuum, depressing the lever and pulling the valve seat away from the orifice, which allows fuel to flow as long as the demand persists. When the vacuum ceases, a spring force pushes on the lever and forces the valve seat against the orifice shutting off the fuel flow. It is important to remember that fuel should not flow through the KN when the engine is not running.

A properly adjusted KN requires a vacuum of only 0.25” to 0.35” of water column to start the opening sequence. Due to this sensitivity, most installations do not need priming to start unless low cranking speeds or restricted and lengthy piping are required. If priming is necessary and a manual primer is installed, use only 1 or 2 second bursts of fuel and immediately try to start the engine. If there is a choke on the carburetor, do not use it as this will probably cause flooding and hard starting. As you can see, the operation of this unit is simple and basic. If you are having trouble operating the engine, in most cases the fuel controller is not malfunctioning. There is generally a problem with the engine or fuel supply. so do not make adjustments or attempt to service the KN until you are sure it is needed.

Figure 4-14 Garretson KN Fuel Valve

Outlet

Mount

Primer (Optional)

Lock–Off

Adjustment

Inlet

Mount

Service

The KN should be periodically checked for leakage past the valve seat and the vents on the cover kept clean and free of obstructions. If the KN needs service we suggest you take it to a qualified serviceman. If that help is not available Garretson will furnish you a list of repair shops with the proper service information.

MN2408 Operation 4-25