Gas line leak testing, Purging, Gas line leak testing purging – State Industries ULTRA FORCE 101 User Manual

Page 40

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40

gas line connection
1. The water heaters covered by this manual are shipped

from the factory with 3/4 inch supply gas connections. The

supply gas line must not be smaller than 3/4 inch. Connect

the supply gas line to the water heater's 24 Volt Gas Valve

in accordance with all applicable local and national code

requirements.

2. Depending on the developed equivalent length and/or the

number of appliances connected to a common main, the size

of the supply gas line may have to be increased, see Gas

Line Sizing on page 39. if the supply gas line must be re-sized

larger to accommodate increased supply gas line lengths or

multiple appliances use reducer couplings and short pipe

nipples to increase the supply gas line as shown in Figure 53.
note: make the transition to the larger supply gas line as

close to the supply gas connection as possible.

FIELD INSTALLED

PIPE NIPPLE

INSTALL A REDUCER

COUPLING WHEN A

LARGER SUPPLY GAS

LINE IS REQUIRED

SUPPLY GAS LINE CONNECTION

120,000 & 150,000 Btu/hr MODELS

24 VOLT

GAS VALVE

TO MAIN

BURNER
FLOW

figure 53

3. Apply thread sealing compounds (pipe dope/Teflon tape)

sparingly and only to the male threads of the pipe joints. Do

not apply sealing compound to the first two threads. Use pipe

dope or Teflon tape marked as being resistant to the action of

liquid petroleum (LP/propane) gases.

LOW GAS PRESSURE

SWITCH

COMBUSTION

BLOWER

SUPPLY GAS CONNECTION

FACTORY INSTALLED

TEE FITTING

SUPPLY GAS LINE CONNECTION

199,000 & 250,000 Btu/hr MODELS

figure 54

4. Use only a smooth jaw adjustable wrench (such as a monkey

wrench) as a back up on the body of the 24 Volt Gas Valve

when tightening the first pipe nipple into the body of the valve.

do not use a standard pipe wrench (Stillson wrench) with

metal tooth jaws as this may permanently damage the valve.

5. Use a standard pipe wrench (Stillson wrench) as a back up

on the first pipe nipple installed above when connecting other

fittings and pipe in the supply gas line to prevent the 24 Volt

Gas Valve on the water heater from twisting during installation.

6. To prevent damage, care must be taken not to apply too

much torque when connecting the supply gas line to the

water heater.

7. install a sediment trap as shown in Figure 52 on page 39.
8. install a main Gas Shutoff valve in the supply gas line as

shown in Figure 52 on page 39.

note: Should overheating occur or the gas supply fail to shut

off, turn off the main Gas Shutoff valve to the water heater.

gas line leak testing

Fire and Explosion Hazard

Leak test before placing the

water heater in operation.
Disconnect gas piping and main

gas shutoff valve before leak

testing.
Install sediment trap in

accordance with NFPA 54.

Use joint compound or Teflon tape

compatible with propane gas.

Any time work is done on the gas supply system perform a leak

test to avoid the possibility of fire or explosion.
1. For test pressures exceeding 1/2 psi (3.45 kPa) disconnect

the water heater and its main Gas Shutoff Valve from the

gas supply piping system during testing, see Figure 52

on page 39. The gas supply line must be capped when

disconnected from the water heater.

2. For test pressures of 1/2 psi (3.45 kpa) or less, the water

heater need not be disconnected, but must be isolated from

the supply gas line by closing the main Gas Shutoff Valve

during testing.

3. Paint all supply gas line joints and connections upstream of

the water heater with a rich soap and water solution to test

for leaks. bubbles indicate a gas leak. Do not use matches,

candles, flame or other sources of ignition for this purpose.

4. repair any leaks before placing the water heater in operation.

purging

Gas line purging is required with new piping or systems in which

air has entered.
Purging should be performed per the current edition of NFPA 54

the National Fuel Gas Code.

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