Laars Mascot II, Installation And Operation Instructions Manual

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LAARS Heating Systems
Page 16
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"
LENGTH MAXIMUM CAPACITY IN THOUSANDS OF BTU PER HOUR
20 200 418
40 137 287
60 110 231
80 94 197
100 84 175
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 6D.
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"
FT CUBIC FEET OF GAS PER HOUR
20 92 190
40 130
60 105
80 90
100
Table 6C.
MASCOT II NATURAL GAS REQUIRED
SIZE CU FT / HR.
125 125
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 6B.
Align total length (pipe and fittings) on left side column of Table 6C
with highest cubic feet of gas required.
Notes:
Consult and confirm with Applicable Fuel Gas Code before beginning
work. Verify gas inlet pressure is between 4 and 13 in W.C. before
starting boiler.
Table 6A.
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 II 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 Tables 6A, 6B, 6C and 6D 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.
WARNING:
Open flame can cause gas to ignite and result in
property damage, severe injury, or loss of life.
NOTE : The Mascot II 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.
EQUIVALENT LENGTHS OF STRAIGHT PIPE FOR TYPICAL SCH 40 FITTINGS
NOMINAL PIPE SIZE
FITTING
1/2" 3/4" 1"
LINEAR FEET
90° ELBOW
3.6 4.4 5.2
TEE
4.2 5.3 6.6
Table 6B.