John Wood Commercial Atmospheric Vent - AJWSM - Manual (Page 13)

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INCH GAGE- 3.5 kPa) SUPPLY GAS PRESSURE. EXPOSURE
TO HIGHER SUPPLY PRESSURE MAY CAUSE DAMAGE
TO THE GAS VALVE WHICH COULD RESULT IN FIRE OR
EXPLOSION. IF OVERPRESSURE HAS OCCURRED SUCH
AS THROUGH IMPROPER TESTING OF GAS LINES OR
EMERGENCY MALFUNCTION OF THE SUPPLY SYSTEM, THE
GAS VALVE MUST BE CHECKED FOR SAFE OPERATION.
MAKE SURE THAT THE OUTSIDE VENTS ON THE SUPPLY
REGULATORS AND THE SAFETY VENT VALVES ARE
PROTECTED AGAINST BLOCKAGE. THESE ARE PARTS
OF THE GAS SUPPLY SYSTEM, NOT THE HEATER. VENT
BLOCKAGE MAY OCCUR DURING ICE STORMS.
IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING
FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING
MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE
INTERNALLY TINNED AND CERTIFIED FOR GAS SERVICE.
BEFORE ATTACHING THE GAS LINE, BE SURE THAT ALL GAS
PIPE IS CLEAN ON THE INSIDE.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE
GAS SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED
SEDIMENT TRAP OR DRIP LEG) MUST BE INCORPORATED
IN THE PIPING (SEE FIG. 11). THE DIRT LEG MUST BE
READILY ACCESSIBLE AND NOT SUBJECT TO FREEZING
CONDITIONS. INSTALL IN ACCORDANCE WITH
FIGURE 12
RECOMMENDATIONS OF SERVING GAS SUPPLIERS.
REFER TO THE CURRENT EDITION OF THE NATIONAL
FUEL GAS CODE.
To prevent damage, care must be taken not to apply too much
torque when attaching gas supply pipe to gas valve inlet.
Apply joint compounds (pipe dope) sparingly and only to the
male threads of pipe joints. Do not apply compounds to the first
two threads. Use compounds resistant to the action of liquefied
petroleum gases.
GAS PIPING AND DIRT LEG INSTALLATION
FIGURE 11
CREATED BY NEEVIA DOCUSTAMP TRIAL VERSION (WWW.NEEVIA.COM) CREATED BY NEEVIA DOCUSTAMP TRIAL VERSION (WWW.NEEVIA.COM)