North American Automatic Shutoff Valves Installation, Operation, Maintenance Instructions
Instructions 1518/1519
OVERVIEW
General Considerations: 1519 Motorized Valves open unattended upon being powered. 1518 Manual Reset Valves should be located so operator is encouraged to confirm main flame ignition after opening valve. Time lag between valve action and flame response is reduced when valve is located near burner, reducing length and storage capacity of downstream piping.
North American Automatic Shutoff Valves are used in fuel supply lines on industrial furnaces, ovens, kilns, boilers, and other heating equipment. They shut off fuel automatically and instantly upon any break in electric power or the safety circuit.They cannot be opened until an interlocking safety or control circuit is complete, restoring power to the valve.
They can be suitable for pipe lines carrying a variety of gases and liquids used in processes other than combustion.
INSTALLATION INSTRUCTIONS - MECHANICAL
Use Manual Reset Valves where "manned" operation is required or preferred.
Read all instructions before installing or operating.
Valves are usually installed upright in horizontal piping. Other orientations are acceptable subject to conditions outlined below:
Specify Motorized Valves where remote or "unmanned" operation is needed. Not recommended for oil applications where on/off cycling is more than 6 cycles per hour. 1518 and 1519 Valves are for emergency automatic shutdown only--following any shutdown, close manual shutoff valves promptly.
Mount valve so that open/shut window indicator will be visible to your operating personnel. The open/shut window indicator should never face downward. With electro-mechanical top assemblies, the motor access side plate should always be vertical to the ground. Valves are usually installed in horizontal piping; however, other orientations are acceptable, subject to the above limitations. The top assemblies of all valves are field rotatable to allow installations involving conflicts with these mounting restrictions. See Top Assembly Rotation section for details. Valves are tolerant of adverse ambient conditions; but, as with any other electrical/mechanical equipment, try to select a location that is cool, clean, and dry. Exposed metal surfaces of valve are aluminum, cast iron, or cast steel all painted. Cover gasketing material is neoprene, or equal. Any substance in atmosphere harmful to these materials will have an adverse effect on the valve exterior. Make no adjustments to the VCS-1 switch. It is factory set as a proof-of-closure switch.
COMPONENT ARRANGEMENT
NFPA 86 insurance underwriters and other agencies or jurisdic- tional authorities require main and pilot gas trains to include two (2) automatic fuel safety shutoff valves (SSOV). Some insurance underwriters also require an automatic normally open vent valve between them. The sequence of components, as arranged in Figure 1, should be adhered to. Equipment Isolation Valve: Always use an approved tight-shut- off manual fuel valve located upstream of automatic valves, to shut off fuel during downtimes.
A gas filter or strainer shall be installed in the fuel gas piping to protect the downstream safety shutoff valves. - See most current version of NFPA 86
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