Gas Connection; Gas Piping; Gas Table - Munchkin T50M Installing, Operating & Maintaining

PART 3. GAS CONNECTION
Failure to follow all precautions could result in fire, explosion or death!
A. GAS CONNECTION
The gas supply shall have a maximum inlet pressure of less
than 14" water column (350 mm), ½ pound pressure (3.4 kPa),
and a minimum of 7" 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)
Nominal
Iron Pipe Internal
Size Diameter
(inches) (inches) 10
3/4 .824 278
1 1.049 520
1 1/4 1.380 1,050
1 1/2 1.610 1,600 1,100
10
WARNING
(Based on a 0.60 Specific Gravity Gas)
Length of Pipe (Feet)
20 30 40 50 60
190 152 130 115 105
350 285 245 215 195 180
730 590 500 440 400 370
890 760 670 610 560
70 80 90 100 125
96 90 84 79
170 160 150 130
350 320 305 275
530 490 460 410

GAS CONNECTION

150 175 200.
72 64 59 55}
120 110 100}
250 225 210}
380 350 320} X 1,000
BTU'S
PER
HOUR