LAARS Mighty Therm LO-NOx PW (Sizes 500-1825) - Install and Operating Manual - Manual (Page 7)

Mighty Therm Lo-NOx Page 7
Table 3. Gas Piping Sizes.
Figure 6. Sediment Trap Installation.
4. The heater and its individual shutoff valve must
be disconnected from the gas supply piping
system during any pressure testing of that system
at test pressures in excess of 1/2 psig. The heater
must be isolated from the gas supply piping
system by closing its individual manual gas
shutoff valve during any pressure testing of the
piping system at test pressures equal to or less
than 1/2 psig.
5. Provide gas supply pressure to the heater as
follows:
Natural
Gas
Max. (inches water column) 10
Min. (inches water column) 6.5
NOTE: the heater and all other gas appliances sharing
the boiler gas supply line must be firing at maximum
capacity to properly measure the inlet supply pressure.
Low gas pressure could be an indication of an
undersized gas meter and /or obstructed gas supply
line.
6.
The correct burner manifold gas pressure is
stamped on the rating plate. The regulator is
preset at the factory and normally requires no
further adjustment.
7. The gas manifold and control assembly is
factory tested and conforms to the safe lighting
and other performance criteria specified in the
latest editions of ANSI Z21.13 and CGA 3.3
Low Pressure Boiler Standard.
8. Before operating the heater, test the complete
gas supply system and all connections for leaks
using a soap solution. Do not use raw flame.
Caution
Since some leak test solutions (including soap
and water) may cause corrosion or stress
cracking, the piping must be rinsed with water
after testing, unless it has been determined
that the leak test solution is noncorrosive.
The heater should be located a safe distance
from Propane gas storage and filling equipment.
Consult local codes and fire protection authorities for
advice on specific installation restrictions.
2.4 Gas Supply and Piping
Review the following instructions before
proceeding with the installation.
1. Verify that the heater is fitted for the proper type
of gas by checking the rating plate. Laars heaters
are normally equipped to operate below a
2000 foot (609.6m) altitude. Heaters equipped to
operate at higher altitudes have appropriate
stickers or tags attached, also printed
information on rating plate.
2. Use the figures in Table 3 to provide adequate
gas piping from the gas meter to the heater.
Figure 5. Incorrect Outdoor Installation.
Distance from Gas Meter
or Last Stage Regulator
Size 0-100' 100-200' 200-300'
500 1½" 2" 2"
715 2" 2" 2½"
999 2" 2½" 3"
1010 2" 2½" 3"
1200 2½" 3" 3"
1430 2½" 3" 3"
1825 2½" 3" 3½"
NOTE: These figures are for Natural Gas (.65 Sp. Gr.), and are
based on 1/2" water column pressure drop. Check supply
pressure with a manometer, and local code requirements for
variations. An average number of tees and elbows have been
taken into account.
3. A sediment trap (drip leg) must be provided
ahead of the gas controls (see Figure 6). A
manual gas shutoff valve must also be provided
for service convenience and safety. A cap must
be provided for cleaning purposes. Check the
local codes.