Unit installation

TURBOPOWER 99

WATER HEATER
PV500-12 07/13 13
9 GAS SUPPLY AND PIPING
Verify that the type of gas specified on rating plate is supplied to the unit. This unit is orificed for operation up to
2000 feet altitude. The appliance Btu/h output, like other similar equipment, derates approximately 4% per 1000
feet above sea level. Consult Factory for installations above 2000 feet elevation.
9.1 Inlet Pressure: Measured at the inlet pressure tap located at the main gas cock. The inlet pressure must remain
within the minimum flow pressure and maximum static pressure charted below while the unit is at rest and while
the unit is operating at maximum firing rate.
Water Heater
Prefix
Min Inlet Flow Pressure
(in. W.C.)
Max Static Pressure
(in. W.C.)
742 5.0" Nat. Gas 14" Nat. Gas
1485 5.5" Nat. Gas 14" Nat. Gas
2228 6.0" Nat. Gas 14" Nat. Gas
2971 11.0" Nat. Gas 14" Nat. Gas
9.2 Manifold Pressure: Measure at the pressure tap on the downstream side of the final manual shutoff valve for
each stage of operation. The rated manifold pressure appears on the data label. The manifold pressure is preset
at the factory and adjustment is not usually required. If adjustment is required, the burner must be firing at the
minimum and/or full rate while the manifold pressure is adjusted.
9.3 Gas Piping Size:
Use the values in “Convert Fittings To Equivalent Straight Pipe” to add the equivalent straight pipe
for each elbow or tee to obtain the total distance from the meter. Use this corrected total distance from the meter for
determining the suggested pipe size in the “Single Unit Installation Suggested Gas Pipe Size” table.
**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.
CONVERT FITTINGS TO EQUIVALENT STRAIGHT PIPE
Fitting Size (inches) ¾" 1" 1¼" 1½" 2" 3" 4" 5"
Equivalent Length of
Straight Pipe (feet)
2' 2' 3' 4' 5' 10' 14' 20'
Equivalent Feet
From Meter
SINGLE UNIT INSTALLATION SUGGESTED PIPE SIZE
Maximum Capacity for Natural Gas*
MBtu/hr Based on 0.5" W.C. Pressure Drop*
1-1/4" 1-1/2" 2" 2½" 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