Gas Supply And Piping; Length Of Standard Pipe Threads; Gas Pipe Sizes - Natural Gas - Bard WG Series Installation Instructions Manual

18. GAS SUPPLY AND PIPING

General Recommendations
1. Be sure the gas line complies with the local codes
and ordinances, or, in their absence, with the
National Fuel Gas Code, ANSI Z223.1, or Natural
Gas Installation Code, CAN/CGA B149.1, or
Propane Installation Code B149.2, latest edition.
2. A sediment trap or drip leg must be installed in the
supply line to the furnace.
3. A ground joint union shall be installed in the gas
line adjacent to and upstream from the gas valve
and downstream from the manual shut off valve.
4. An 1/8" NPT plugged tapping accessible for test
gauge connection shall be installed immediately
upstream of the gas supply connection to the
furnace for the purpose of determining the supply
gas pressure. This can be omitted if local codes
permit use of plugged tapping in gas valve inlet.
5. Install listed manual shut off valve in the supply
gas line external to and immediately upstream of
the furnace (see Figure 11).
6. Use steel or wrought iron pipe and fittings.
7. DO NOT thread pipe too far. Valve distortion or
malfunction may result from excess pipe within
the control. Use pipe joint compound resistant to
the action of liquefied petroleum gases on male
threads only. DO NOT use Teflon tape. See Table
5 and Figure 12.
TABLE 5
Length of Standard Pipe Threads (Inches)
Effective Length
Pipe Size
of Thread
3/8
3/4 1/2 - - 9/16
1
FIGURE 12
Proper Piping Practice
Manual 2100-587J
Page 26 of 59
Overall Length
of Thread
1/2 9/16
13/16
9/16 1
8. Refer to Table 6 for Gas Pipe Sizes for natural
gas. If more than one appliance is supplied from a
single line size, capacity must equal or exceed the
combined input to all appliances, and the branch
lines feeding the individual appliances properly
sized for each input.
THIS PRODUCT MUST BE GAS PIPED
BY A LICENSED PLUMBER OR GAS
FITTER IN THE COMMONWEALTH OF
Length
of Pipe –
Feet
10
20
30
40
50
60
70
80
100
Checking the Gas Piping
Before turning gas under pressure into piping, all
openings from which gas can escape should be closed.
Immediately after turning on gas, the system should be
checked for leaks. This can be done by watching the
1/2 cubic foot test dial and allowing 4 minutes to show
any movement, and by soaping each pipe connection
and watching for bubbles. If a leak is found, make the
necessary repairs immediately and repeat the above
test. The furnace must be isolated from the gas supply
piping system by closing the manual shut off valve
on the combination gas control valve during pressure
testing of the gas supply piping system at pressures
up to 1/2 PSIG. The furnace and its individual shut
off valve must be disconnected from supply piping and
supply piping capped during any pressure testing of
supply piping system at test pressures in excess of 1/2
PSIG.
Defective pipes or fittings should be replaced and
not repaired. Never use a flame or fire in any form to
locate gas leaks; use a soap solution.
After the piping and meter have been checked
completely, purge the system of air. DO NOT bleed air
inside the furnace. Be sure to check and relight all
the gas pilots on other appliances that may have been
MIS-897
extinguished because of interrupted gas supply.
MASSACHUSETTS.
TABLE 6
Gas Pipe Sizes – Natural Gas
Pipe Capacity –
BTU per Hour Input Pipe Size
1/2" 3/4"
132,000 278,000 520,000 1,050,000
92,000 190,000 350,000
73,000 152,000 285,000
63,000 130,000 245,000
56,000 115,000 215,000
50,000 105,000 195,000
46,000 96,000 180,000
43,000 90,000 170,000
38,000 79,000 150,000
1" 1-1/4"
730,000
590,000
500,000
440,000
400,000
370,000
350,000
305,000