2 manifold pressure – Waterpik Technologies LG User Manual

Page 13

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Model LG Pool and Spa Heater

Page 11

Table 4. Natural Gas Pipe Size Requirements*

Distance from Gas Meter

0-50 feet

50-100 feet

100-200 feet

Heater

(0-15 m)

(15-30 m)

(30-60 m)

Size

in.

(mm)

in.

(mm)

in.

(mm)

125

3/4

(19)

1

(25)

1

(25)

175

1

(25)

1

(25)

1-1/4

(32)

250

1

(25)

1-1/4

(32)

1-1/4

(32)

325

1-1/4 (32)

1-1/4

(32)

1-1/2

(38)

400

1-1/4 (32)

1-1/2

(38)

1-1/2

(38)

Notes:

*1. These numbers are for natural gas (0.65 Sp. Gr.) and are

based on 1/2 inch (13mm) water column pressure drop.
Check supply pressure with a manometer, and local code
requirements for variations. For liquefied petroleum gas,
reduce pipe diameter one size, but maintain a3/4inch (19mm)
minimum diameter.

2.Check supply pressure and local code requirements before

proceeding with work.

3.Pipe fittings must be considered when determining gas pipe

sizing.

4.

Install a sediment trap (drip leg) ahead of the gas
controls (see Figure 6). Fit the trap with a
threaded cap which can be removed for cleaning.

5.

Install a manual gas shutoff valve for service and
safety. Do not use a restrictive gas cock. DO
NOT USE FLEXIBLE GAS PIPING, it will
restrict the gas flow to the heater.

6.

Disconnect the heater and its individual shutoff
valve from the gas supply system during pressure
testing of the system at pressures higher than 1/2
pounds per square inch (psi) (3.45 kilopascals
[kPa]). If the test pressure is equal to or less
than 1/2 psi (3.45 kPa), close the manual shutoff
valve on the heater during the piping pressure
test.

7.

If the gas supply pressure is less than required,
check for undersized pipe between the meter and
the heater, a restrictive fitting, or an undersized
gas meter. Gas supply pressures to the heater
are listed in Table 5.

NOTE: The maximum inlet gas pressure must
not exceed the specified value. The minimum
value listed is for the purpose of input
adjustment. Refer to Table 5.

Supply Pressure

Minimum

Maximum

Natural Gas

5.5 Inches WC

10.0 Inches WC

(1.4 kPa)

(2.5 kPa)

LP Gas

10.0 Inches WC

14.0 Inches WC

(2.5 kPa)

(3.5 kPa)

Manifold Pressure Nominal

Natural Gas

4.0 Inches WC (1.0 kPa)

LP Gas

9.0 Inches WC (2.2 kPa)

Table 5. Gas Supply Pressure Requirements

Figure 6. The proper design for a sediment trap/drip leg.

8.

Before operating the heater, test the complete
gas supply system and all connections for leaks
using a soap solution. Do not use an open flame.

CAUTION

Some leak test solutions (including soap and
water) may cause corrosion or stress cracking.
Rinse the piping with water after testing.

ATTENTION

Certaines solutions d’essai d’étanchéité (y
compris l’eau et le savon) peuvent causer de la
corrosion ou de la fissuration. Rincez les
tuyaux à l’eau après l’essai d’étanchéité.

4.2 Manifold Pressure

Confirm that gas supply pressure is correct. If

the gas supply pressure is less than required, check for
undersized pipe between the meter and the heater, a
restrictive fitting, or an undersized gas meter. Gas
supply pressures to the heater, when it is operating,
are listed in Table 5.

CAUTION

Manifold gas pressure for the Lite2 Lg natural
gas heaters should be set at 4" WC. Propane
heaters should be set to 9" WC.

ATTENTION

La pression du collecteur de pression pour les
systèmes de chauffage au gaz naturel devrait
être de 4'’ WC. Pour les sytèmes de chauffage
au gaz propane devrait être de 9'’ WC.

The manifold pressure may be checked by con-

necting a manometer to the pressure port on the outlet
side of the valve. You will need to remove the 1/8"

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