Munchkin HIGH EFFICIENCY HEATER with the "925" Controller - Manual (Page 12)

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GAS CONNECTION
PART 3. GAS CONNECTION
A. GAS CONNECTION
The gas supply shall have a maximum inlet pressure of less
than 14" water column (350 mm), ½ pound pressure (3.5 kPa),
and a minimum of 3.5" water column. The entire piping
system, gas meter and regulator must be sized properly to
prevent pressure drop greater than 0.5" as stated in the National
Fuel Gas Code. This information is listed on the rating plate. It is
very important that you are connected to the type of gas as noted on
the rating plate. "LP" for liquefied petroleum, propane gas or, "Nat"
natural or city gas. All gas connections must be approved by the local gas supplier, or utility in addition
to the governing authority, prior to turning the gas supply on. The nipple provided is ½" and it is
mandatory that a ¾" to ½" reducing coupling (provided) is used, threaded into the branch of a ¾" tee,
and a drip leg fabricated, as per the National Fuel Gas code. You must ensure that the entire gas line
to the connection at the Munchkin is no smaller than ¾". Once all the inspections have been
performed, the piping must be leak tested. If the leak test requirement is a higher test pressure than
the maximum inlet pressure, you must isolate the Munchkin from the gas line. In order to do this, you
must shut the gas off using factory and field-installed gas cocks (following the lighting instructions in
Part 6 Section B.) This will prevent high pressure. Failure to do so may damage the gas valve. In the
event the gas valve is exposed to a pressure greater than ½ PSI, 14" water column, the gas valve must
be replaced. Never use an open flame (match, lighter, etc.) to check gas connections.
B. GAS PIPING
1. Run the gas supply line in accordance with all applicable codes.
2. Locate and install manual shutoff valves in accordance with state and local requirements.
C. GAS TABLE
Refer to Table (1) to size the supply piping to minimize pressure drop between meter or regulator
and unit.
Maximum Capacity of Pipe in Cubic Feet of Gas per Hour for Gas Pressures of 0.5 psi or Less and a
Pressure Drop of 0.3 Inch water Column
(TABLE 1) (Based on a 0.60 Specific Gravity Gas)
Nominal
Iron Pipe Internal
Length of Pipe (Feet)
Size Diameter
(inches) (inches) 10 20 30 40 50 60 70 80 90 100 125 150 175 200.
3/4 .824 278 190 152 130 115 105 96 90 84 79 72 64 59 55} BTU'S
1 1.049 520 350 285 245 215 195 180 170 160 150 130 120 110 100} PER
1 1/4 1.380 1,050 730 590 500 440 400 370 350 320 305 275 250 225 210} HOUR
1 1/2 1.610 1,600 1,100 890 760 670 610 560 530 490 460 410 380 350 320} X 1,000
WARNING
Failure to follow all precautions could result in fire, explosion or death!