10
TABLE 5
Multipliers To Be Used With Table 1 When Applying The
Gravity Factor To Other Than .60 Specific Gravity
Specific
Specific
Gravity
Multiplier
Gravity
Multiplier
.35
1.31
1.00
.78
.40
1.23
1.10
.74
.45
1.16
1.20
.71
.50
1.10
1.30
.68
.55
1.04
1.40
.66
*.60 (Nat.)
1.00
*1.50 (Prop.)
.63
.65
.96
1.60
.61
.70
.93
1.70
.59
.75
.90
1.80
.58
.80
.87
1.90
.56
.85
.84
*2.00 (Butane)
.55
.90
.82
2.10
.54
*Use these correction factors if exact specific gravity of the gas is not known.
PURGING
Gas line purging is required with new piping or systems in which
air has entered.
CAUTION
PURGING SHOULD BE PERFORMED BY PERSONS
EXPERIENCED IN THIS TYPE OF GAS SERVICE TO AVOID RISK
OF FIRE OR EXPLOSION. PURGE DISCHARGE MUST NOT
ENTER CONFINED AREAS OR SPACES WHERE IGNITION CAN
OCCUR. THE AREA MUST BE WELL VENTILATED AND ALL
SOURCES OF IGNITION MUST BE INACTIVATED OR REMOVED.
BEFORE PLACING THE BOILER IN OPERATION, CHECK FOR
GAS LEAKAGE. Use soap and water solution or other material
acceptable for the purpose in locating gas leaks. DO NOT USE
MATCHES, CANDLES, FLAME OR OTHER SOURCES OF
IGNITION FOR THIS PURPOSE.
1.
CORRECT GAS
Make sure the gas on which the boiler will operate is the same as
that specified on the boiler rating plate. Do not install the boiler if
equipped for a different type gas, consult your gas supplier. These
boilers are designed to operate on natural gas only.
2A. SIZING GAS SUPPLY LINE (For single boiler installations
and for installations of multiples of two or three of same size
boilers).
Use table 1, which is taken from ANSI booklet Z223.1, NATIONAL
FUEL GAS CODE, and/or CAN/CSA-B149.1-00 to size iron pipe
or equivalent gas supply line. Table 4 is based on a pressure drop
of 0.3 inches of water and a specific gravity of 0.60 which is
approximately for natural gas. (LP gas has an S.G. of about 1.53).
If the service pressure is five inches water column or less, use one
pipe size larger than specified in table 1 in order to minimize pressure
drop in the line.
2B.
SIZING GAS SUPPLY LINE (For multiples of over three boilers
of same size or for multiple installations of two or more mixed
sizes).
Capacities in cubic feet per hour of 0.60 specific gravity gas for
different sizes and lengths are shown in table 4. No additional
allowance is necessary for an ordinary number of fittings.
Where it is necessary to use more than the average number of
pipe fittings i.e. elbows, tees, and valves in gas supply line, use a
pipe larger than specified to compensate for increased pressure
drop.
TABLE 4
MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR (BASED UPON A PRESSURE DROP OF
0.3 INCH WATER COLUMN AND 0.6 SPECIFIC GRAVITY GAS)
Length in Feet (Meters)
Nominal Iron Pipe Size, Inches (NPT)
From Gas Meter
1/2
3/4
1
1 1/4
1 1/2
2
2 1/2
3
4
10 (3)
132
278
520
1,050
1,600
3,050
4,800
8,500
17,500
20 (6)
92
190
350
730
1,100
2,100
3,300
5,900
12,000
30 (9)
73
152
285
590
890
1,650
2,700
4,700
9,700
40 (12)
63
130
245
500
760
1,450
2,300
4,100
8,300
50 (15)
56
115
215
440
670
1,270
2,000
3,600
7,400
60 (18)
50
105
195
400
610
1,150
1,850
3,250
6,800
70 (21)
46
96
180
370
560
1,050
1,700
3,000
6,200
80 (24)
43
90
170
350
530
990
1,600
2,800
5,800
90 (27)
40
84
160
320
490
930
1,500
2,600
5,400
100 (30)
38
79
150
305
460
870
1,400
2,500
5,100
125 (38)
34
72
130
275
410
780
1,250
2,200
4,500
150 (46)
31
64
120
250
380
710
1,130
2,000
4,100
175 (53)
28
59
110
225
350
650
1,050
1,850
3,800
200 (61)
26
55
100
210
320
610
980
1,700
3,500
*The heating value of natural gas is approximately 1050 Btu/ft³.
Propane (L.P.) gas has a heating value of approximately 2500 Btu/ft³.
