LAARS Mascot LX MLXC 175 MBH - Install and Operating Manual - Manual (Page 21)

Mascot LX Boilers and Water Heaters Page 17
WARNING:
Open flame can cause gas to ignite and result in
property damage, severe injury, or loss of life.
NOTE: The Mascot LX 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.
SCHED 40 METAL PIPE CAPACITY FOR 1.50 SPECIFIC GRAVITY
UNDILUTED PROPANE
NOMINAL PIPE SIZE @ 11" W.C. INLET AND 0.5" W.C. PRESSURE DROP
SIZE 1/2" 3/4" 1"
LENGTH MAXIMUM CAPACITY IN THOUSANDS OF BTU PER
HOUR
20 200 418 787
40 137 287 541
60 110 231 434
80 94 197 372
100 84 175 330
NOTES: 1. Follow all local and national LP gas codes for line sizing and
equipment requirements. 2. Verify that inlet gas pressure remains between
4 and 13 inches of water column before and during operation.
Source: ANSI Z223.1-80 National Fuel Gas Code.
Table 9. Nominal Pipe Size, Propane
SCH 40 METAL PIPE CAPACITY FOR 0.60 SPECIFIC GRAVITY NATURAL GAS
NOMINAL PIPE SIZE @ 0.30" W.C. PRESSURE DROP
LENGTH 1/2" 3/4" 1"
FT CUBIC FEET OF GAS PER HOUR
20 92 190 350
40 130 245
60 105 195
80 90 170
100
Table 10. Nominal Pipe Size, Natural Gas
SECTION 4.
Gas Supply and Piping
4.1 Gas Supply and Piping
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. Mascot LX will
function properly without the use of high altitude
modification at elevations up to 10,000 feet (3050
m).
2. The maximum inlet gas pressure must not exceed
13" W.C. (3.2kPa). The minimum inlet gas pressure
is 4" W.C. (1.0kPa).
3. Refer to Table 11, Table 10, Table 9 and Table 12 to
size 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.