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
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.
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.
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