AAO Valves

Air Shutoff Valves

• Sizes: Valves come in sizes 2” thru 8” nominal connections

• Air Pressure to Open / Spring to Close (failsafe)
• Part of the A Series of easily installed, compact, air intake valves for diesel engine emergency shut down.
• New Speed Switch Kit available for a complete overspeed installation

The AAO version of the FPE A Series of shutdown valves is designed to be installed in the air intake system of a diesel engine to provide an emergency means of rapid shutdown.

The AAO valve is suitable for applications where there is a supply of filtered dry or lubricated air (or inert gas) available form 3 to 8 Bar (43 to 116 psi).This air supply is used to close the AAO valve thereby bringing the running engine to a stop within a few seconds in an emergency. Venting of the air pressure signal results in the automatic reset of the valve to the open condition. This mode of operation makes the AAO valve suitable for applications where non-failsafe operation is permitted such as emergency vehicles etc.

A shutdown control system is required to automatically vent the air pressure signal to the AAO when engine overspeed or any other selected fault condition, including loss of the supply air pressure, is sensed.

Important Note: A manual emergency shutdown button should also be incorporated in the shutdown control system. The low intake air flow restriction through the open valve makes it generally compatible with the requirements of low emission diesel engines.

Corrosion resistant materials are used where applicable in the construction of the valve. This lightweight and compact valve design together with the availability of factory fitted hose adaptors selected from a wide range of optional sizes assists in easy installation.

The valve may be fitted to either turbocharged or naturally aspirated engines. In the case of turbocharged engines temperature limitations may restrict the position in which the valve may be installed in the intake system.