Harsco Industrial 1004905923 Installation & Owner's Manual page 22

The boiler must be disconnected at the boiler manual shutoff valve (located at the end of the supplied gas train)
from the gas supply piping system during any pressure testing of the system at pressures in excess of 1/2 psig
(14" W.C.).
During any pressure testing of the gas supply piping system at pressures equal to or less than 1/2 psig (14"
W.C.), the boiler should be isolated from the gas supply piping system by closing the manual shut-off.
Some leak test solutions, including soap and water, may cause corrosion. These solutions should be rinsed off
with water after testing.
RECOMMENDED GAS PIPING INSTALLATION
Gas
Remote Gas
Supply
Shutoff
Drip Leg
Field Gas Piping
Install a sediment trap (drip leg) and a union connection should be installed upstream of the primary manual
shutoff valve on the boiler. Gas piping should be installed in accordance with National Fuel Gas Code, NFPA
54/ANSI Z223.1, latest edition, and any other local codes which may apply. In Canada, please refer to CAN/CSA-
B149.1
Pipe Capacity for Natural Gas
NOTICE! See Pipe Capacity for Natural Gas chart for required pipe size, based on overall length of pipe from
meter plus equivalent length of all fittings. Approximate sizing may be based on 1 cubic foot of natural gas per
1,000 Btu per hour input, i.e., 3,000,000 Btu per hour requires about 3,000 cubic feet per hour.
Nominal
Iron Pipe Internal
Size Diameter
(Inches) (Inches)
2 2.067
2-1/2 2.469
3 3.068
4 4.026
Boiler Main Gas
Valve
Union
Equivalent Pipe
Length
90º Ell Tee
(Feet) (Feet)
5.17 10.3
6.16 12.3
7.67 15.3
10.1 20.2
®
MODU-FIRE Forced Draft Gas-Fired Boiler 2500-3000
Maximum Capacity in Cubic Feet of Natural Gas per Hour
Pressure Drop of 0.5 inch Water Column/Equivalent Length of
20 40 60
2,750 1,900 1,520
4,350 3,000 2,400
7,700 5,300 4,300
15,800 10,900 8,800
22
Pipe (in feet)
80 100
1,300 1,150
2,050 1,850
3,700 3,250
7,500 6,700
150 200
950 800
1,500 1,280
2,650 2,280
5,500 4,600