Laars Neotherm NTH, Installation And Operation Instruction Manual

Page: 31 / 104

Page 31
SECTION 4
GAS SUPPLY AND PIPING
All Installations must conform to the National Fuel
Gas Code ANSI Z223.1/NFPA54, and/or local codes.
In Canada, the installation must conform to the latest
edition of CSA B149.1 Natural Gas and Propane
Gas Installation Code, and/or local codes. Gas piping
should be supported by suitable hangers or floor
stands, not the appliance.
Review the following instructions before proceeding
with the installation.
1. Verify that the appliance is fitted for the proper type of
gas by checking the rating plate. The unit will function
properly without the use of high altitude modification
at elevations up to 10,000 feet (3050 m).
2. Verify that the Min and Max inlet gas supply
pressures are within the parameters shown in
Table 8.
3. Refer to Table 9 to size the piping.
4. Run gas supply line in accordance with all
applicable codes.
5. Locate and install manual shutoff valves in
accordance with state and local requirements.
6. A sediment trap must be provided upstream of the
gas controls.
7. All threaded joints should be coated with
piping compound resistant to action of liquefied
petroleum gas.
8. The appliance and its individual shutoff valve
must be disconnected from the gas supply piping
during any pressure testing of that system at test
pressures in excess of 1/2 PSIG (3.45kPa).
9. The unit must be isolated from the gas supply
system by closing its individual manual shutoff
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less
than 1/2 PSIG (3.45kPa).
10. The appliance and its gas connection must be leak
tested before placing it in operation.
11. Purge all air from gas lines.
Notes:
Consult and confirm with Applicable Fuel Gas Code before
beginning work. Verify gas inlet pressure is correct using
Table 8 before starting boiler.
NOTE : This appliance and all other gas appliances
sharing the gas supply line must be firing at maximum
capacity to properly measure the inlet supply pressure.
The pressure can be measured at the supply pressure
port on the gas valve. Low gas pressure could be an
indication of an undersized gas meter, undersized
gas supply lines and/or an obstructed gas supply
line. Some units are equipped with low and high gas
pressure switches that are integrally vent limited.
These types of devices do not require venting to
atmosphere.
WARNING
If an inline high gas pressure regulator is used, it MUST
BE of the lockup type and located a minimum of 10 feet
from the unit. Failure to do so may result in insufficient
gas volume supplied to the unit.
Inlet Gas Supply Pressure
Min”
Max
Natural Gas
3.5” W.C. 10.5” W.C.
Propane 8” W.C. 13” W.C.
Table 8. Gas Pressure
Table 9.
To Size Your Gas Piping
Required
Propane
Natural Gas
Size
CU FT/
HR
Size
CU FT/
HR
150 60 150 150
199 80 199 199
285 114 285 285
399 160 399 399
500 200 500 500
600 240 600 600
750 300 750 750
850 340 850 850
To size piping:
Measure linear distance from meter outlet to last boiler.
Add total input of all boilers and divide by 1000 to obtain
cu ft / hr required. Add total equivalent length of fittings
used according to Table 10 on page 32. Align total
length (pipe and fittings) on left side column of Table 11
on page 32 with highest cubic feet of gas required.
WARNING:
Open flame can cause gas to ignite and result in
property damage, severe injury, or loss of life.
N
EO
T
HERM
Commercial Boilers and Water Heaters