EMX, EMXO and EMXGO SERIES WATER BOILERS
34-503 07/13
13
15 GAS PIPING
1. Before making gas hook-up, verify that the unit is being supplied with same gas type as indicated on the
data decal.
2. The maximum inlet gas pressure must not exceed the value specified. If delivery pressure is higher, a
single suitable intermediate, lock-up type regulator must be installed ahead of the low-pressure regulator
on the burner to reduce inlet pressure to acceptable limits. The regulator must have a flow regulating
capacity suitable for the firing rate.
3. The gas supply line must be of sufficient size for length of run and pressure drop to furnish adequate gas
pressure to allow the burner to develop its rated capacity. A drip leg should be installed ahead of burner
piping connection, if not supplied (See Table 1).
4. Gas valves and gas regulators may contain bleed or vent ports. Local codes may require bleeds and
vents to be vented to atmosphere outside the building. Consult local building codes for size and
installation.
Equivalent
feet from
meter
PIPE SIZE
Maximum Capacity for Natural Gas*
MBTU/HR Based on 0.5" W.C. Pressure Drop*
1-1/4" 1-1/2"
2"
2
½"
3" 4"
25 860 1320 2475 3900 7000 -
40 660 990 1900 3000 5300 -
60
-
810 1520 2400 4300 -
80
-
690 1300 2050 3700 -
100
-
620 1150 1850 3250 6700
125
-
- 1020 1650 2950 6000
150 - - 950
1500
2650
5500
175 - - 850
1370
2450
5000
200 - - 800
1280
2280
4600
TABLE 1
*Multiplier for Propane: 1.57
**Multiplier for alternate pressure drops:
0.3" W.C. 0.77; 1.0" W.C. 1.41; 2.0" W.C. 2.00; and 4.0" W.C. 2.82.
CAUTION: Be sure gas supply and vent lines have been cleaned of all debris, which could enter the
regulators or burner system and cause malfunction or unsafe conditions. Pipe joint sealant should be
used instead of tape and should be resistant to liquefied petroleum when LP gas is used.
16 OIL TANK AND SUPPLY LINES FOR OIL AND COMBINATION GAS/OIL WATER HEATERS
1. The oil tank construction and installation must meet local codes and should meet the specifications
recommended by Underwriter's Laboratories (see Figure 3).
IMPORTANT:
The combination gas/oil burner requires a constant supply of fuel oil for pump lubrication, even
when running on gas. Make sure the oil shutoff valve is open and oil is available at the pump when the burner
is in service. If no oil supply is available and burner must be run on gas, remove the oil pump coupling on
burner.
A two-pipe system must be used at the burner inlet. A single pipe system may be used to supply local holding
tanks at Individual burners (up to 50 gallons, or check your local codes), but provisions must be made for a
return line from the burner oil pump to the holding tank. When a gravity feed system is used install anti-siphon
valve close to tank in supply line.