Part 3 3-a. gas connection, B. gas piping, C. gas table – HTP Munchkin High Efficiency Heater User Manual
Page 5

PART 3
3-A. GAS CONNECTION
The gas supply shall have a maximum inlet pressure of less than 14" water
column (350 mm), ‰ 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, or 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 ‰" and it is mandatory that a " to ‰" reducing bushing (provided) is used, threaded into the branch of
a " 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
". 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 following lighting instruction on page 11. Unscrew the
threaded mounting flange which is located on the gas valve which will prevent high pressure which may damage the gas
valve. In the event the gas valve is exposed to a pressure greater than ‰ PSI, 14" water column, the gas valve must be
replaced. Never use an open flame (lit match, lighter) to check gas connections.
3-B. GAS PIPING
1.
Run gas supply line in accordance with all applicable codes.
2.
Locate and install manual shutoff valves in accordance with state and local requirements.
3-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)
WARNING
Failure to follow all precautions could result in fire, explosion or death!
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
3