Burnham Minuteman II, Инструкция по установке, эксплуатации и обслуживанию

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10
V. Gas Piping
A.
Size gas piping. Design system to provide adequate gas
supply to boiler. Consider these factors:
1. Allowable pressure drop from point of delivery to
boiler. Maximum allowable system pressure is ½
psig. Actual point of delivery pressure may be less;
contact gas supplier for additional information.
Minimum gas valve inlet pressure is stamped on the
rating label located in the boiler's vestibule
compartment.
2. Maximum gas demand. Table 2 lists boiler input
rate. Also consider existing and expected future gas
utilization equipment (i.e. cooking equipment).
3. Length of piping and number of fittings. Refer to
Table 3 for maximum capacity of Schedule 40 pipe.
Table 4 lists equivalent pipe length for standard
fittings.
4. Specific gravity of gas. Gas piping systems for gas
with a specific gravity of 0.60 or less can be sized
directly from Table 3, unless authority having
jurisdiction specifies a gravity factor be applied. For
specific gravity greater than 0.60, apply gravity
factor from Table 5. If exact specific gravity is not
shown choose next higher value.
For materials or conditions other than those listed
above, refer to National Fuel Gas Code , NFPA 54/
ANSI Z223.1, or size system using standard
engineering methods acceptable to authority having
jurisdiction.
B.
Connect boiler gas valve to gas supply system.
1. Use methods and materials in accordance with local
plumbing codes and requirements of gas supplier. In
absence of such requirements, follow National Fuel
Gas Code , ANSI Z223.1.
2. Use thread (joint) compounds (pipe dope) resistant
to action of liquefied petroleum gas.
3. Install sediment trap, ground-joint union and manual
shut-off valve upstream of boiler gas control valve
and outside of jacket. See Figure 8.
4. All above ground gas piping upstream from manual
shut-off valve must be electrically continuous and
bonded to a grounding electrode. Do not use gas
piping as grounding electrode. Refer to National
Electrical Code , ANSI/NFPA 70.
Table 2: Rated Input
Table 3: Maximum Capacity of Schedule 40 Pipe in CFH For Gas Pressures of 0.5 psig or Less
Boiler
Model
Input Rate
[cubic feet per hour]
Gas Connection
Size (Inches)
Natural
Gas
LP Gas
MMII4-70 70 28 ½
MMII4-105 105 42 ½
MMII5-105 105 42 ½
MMII5-140 140 56 ½
Length
[Feet]
0.3 Inch w.c. Pressure Drop 0.5 Inch w.c. Pressure Drop
½ ¾ 1 1¼ ½ ¾ 1 1¼
10 132 278 520 1,050 175 360 680 1,400
20 92 190 350 730 120 250 465 950
30 73 152 285 590 97 200 375 770
40 63 130 245 500 82 170 320 660
50 56 115 215 440 73 151 285 580
60 50 105 195 400 66 138 260 530
70 46 96 180 370 61 125 240 490
80 43 90 170 350 57 118 220 460
90 40 84 160 320 53 110 205 430
100 38 79 150 305 50 103 195 400