7GAS 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. Appliance Btuh output derates 4% per 1000 feet elevation above sea level. Consult Factory for installations above 2000 feet elevation.
7.1Gas Train and Controls Certification
NOTE: The gas train and controls assembly provided on this unit have been tested under the applicable American National Standard to comply with safety and performance criteria such as proper ignition, combustion and safety shutdown operation.
7.2Gas Control Trains
All models include gas control trains with the following components: main manual shutoff valve, two safety shutoff valves, proportionator regulator and a final manual valve with the manifold pressure tap on the side of the valve. These components may be separate or two or more may be combined in a common housing.
Caution: Do not adjust or remove any screws or bolts on gas train control components which are sealed with a red or blue colored compound. Doing so will void all approvals and warranties.
7.3Inlet Pressure
Measure at the inlet pressure tap located at the main gas cock. The inlet pressure must remain within the minimum and maximum values while the unit is at rest and while the unit is operating at maximum firing rate.
INLET PRESSURE | NAT. GAS |
Maximum Static Pressure | 14" |
Minimum Flow Pressure | 4.5" |
7.4 Manifold Pressure
LP
14"
11"
Measure at the pressure tap located downstream side of the manual valve closest to the burner. The rated manifold pressure appears on the product data label located near the front of the appliance.
7.5Gas 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.
CONVERT FITTINGS TO EQUIVALENT STRAIGHT PIPE
Diameter Fitting (inches) | ¾" | 1" | 1¼" | 1½" | 2" | 3" | 4" | 5" |
Equivalent Length of Straight Pipe (feet) | 2' | 2' | 3' | 4' | 5' | 10' | 14' | 20' |
Use this corrected total distance from the meter for determining the suggested pipe size in the “Single Unit Installation Suggested Gas Pipe Size” table.
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| SINGLE UNIT INSTALLATION SUGGESTED PIPE SIZE |
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Equivalent Feet |
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| Maximum Capacity for Natural Gas* |
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| MBTU/HR Based on 0.5" W.C. Pressure Drop** |
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From Meter |
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| 2" | 2½" | 3" | 4" | |||
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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 |
*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.
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