Gas Connections; Gas Pipe Sizing - Pentair ETi 400 Instructions D'installation

GAS CONNECTIONS

GAS LINE INSTALLATIONS
Before installing the gas line, be sure to check which gas the heater has been designed to burn. This is important because
different types of gas require different gas pipe sizes. The rating plate on the heater will indicate which gas the heater is
designed to burn. The Table 2 below, show which size pipe is required for the distance from the gas meter to the heater.
The table description is for natural gas at a specific gravity of 0.60, and propane gas at a specific gravity of 1.50.
When sizing gas lines, calculate three (3) additional feet of straight pipe for every elbow used. When installing the gas
line, avoid getting dirt, grease or other foreign material in the pipe as this may cause damage to the gas valve, which
may result in heater failure.
The gas meter should be checked to make sure that it will supply enough gas to the heater and any other appliances that
may be used on the same meter. The gas line from the meter will usually be of a larger size than the gas valve supplied
with the heater. Therefore a reduction of the connecting gas pipe will be necessary. Make this reduction as close to the
heater as possible.
The heater requires a gas supply of not less than 4 in (10.2 cm) wc, and not more than 10.5 in (27 cm) wc for natural gas,
and not more than 14 in (36 cm) wc for propane gas. Gas supply pressures outside of this range may result in improper
burner operation. A minimum flowing or dynamic inlet pressure (while the heater is running) of 4 in (10.2 cm) wc is
required to maintain input rating with no more than a 2 in pressure drop between static and dynamic. The gas supply must
be installed in accordance with the National Fuel Gas Code, ANSIZ223.1, or standard CSA B149.1, Natural Gas and
Propane Installation Codes, as applicable and all applicable local codes. Install a manual shut-off valve and a sediment
trap and union located outside the heater panels, see Figure 15. Do not use a restrictive gas cock. The following minimum
gas pipe sizes are recommended for natural gas supply piping, see Table 2 on below. For low pressure LP gas, pipe size
may be reduced by 1/4-in, with a minimum pipe size of 1/2-in. Check for compliance with local codes.
The heater and any other gas appliances must be disconnected from the gas supply piping system during any pressure
testing on that system, (greater than ½ PSI). The heater and its gas connection must be leak tested before placing the
heater in operation. Do not use flame to test the gas line. Use soapy water or another nonflammable method.
A manual main shut-off valve must be installed externally to the heater.
DO NOT INSTALL THE GAS LINE UNION INSIDE THE HEATER CABINET. THIS WILL VOID YOUR WARRANTY.

GAS PIPE SIZING

STAGE TWO LOW PRESSURE GAS PIPE SIZING
Maximum Equivalent Pipe Length (ft)
Natural Gas 1000 BTU/FT
0.60 Specific Gravity at 0.5 in. WC Pressure Drop
Propane Gas 2500 BTU/FT
1.50 Specific Gravity at 0.5 in. WC Pressure Drop
Input 3/4"
Model (KBTU) N
ETi ™
399.0 *
400
Rev. C 4/2017
3
3
1" 1-1/4"
P N P N P
20 20 60 90 220 200 450
Section 2: Installation Instructions
NOTE
WARNING
Table 2: Note (*) A 3/4" gas line can be used for up to
2 ft (61 cm) maximum length from the gas valve in addition
to the sediment trap.
1-1/2"
N P
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