American Dryer Corp. AD-670 - Manual (Page 35)

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SECTION VIII
GAS TRAIN AND BURNER DESCRIPTION AND OPERATION
The ADG-670’s atmospheric burner system is responsible for supplying the dryer with it’s heat input. It is a
high/low system with a firing rate of 2.2 million BTUs per hour (554,400 kcal/hr) on hi-fire and 450,000 BTUs
per hour (113,400 kcal/hr) on lo-fire. This system consists of four (4) main parts: the pilot gas supply line, the
main gas supply line, the lo-fire gas loop, and the atmospheric line burner.
A. PILOT GAS SUPPLY LINE
The pilot gas supply line is the 1/2” line which tees off the main gas supply line just after the main internal
regulator. This line supplies the gas for the standing pilot. It is the standing pilot that is used to ignite the main
flame.
1. 1/2” N.P.T. Gas Pilot Regulator – The 1/2” regulator on this line is used to regulate the gas pressure down
to 1/2 PSI (0.03 bars). The regulator comes preset from the factory for both natural and liquid propane
(L.P.) gases and should not need adjustment.