Midco Unipower A-Series - Manual (Page 9)

VII Gas Piping Cont.
VIII Burner Start-Up
■ ■ ■ ■ In higher gas pressure systems (over 14" W.C.) it is very important to install the proper
pressure reducing regulators at the burner. A high pressure regulator must be used in the line
ahead of the burner main manual gas valve, but it must be of the tight shut-off type and must
have a minimum flow regulating capacity suitable for the pilot (20,000 BTU/hr.)
CAUTION: If the gas supply pipeline is to be pressure tested, it should be done
before the burner is connected in order to prevent damage to the burner pressure
regulators and main gas valve. Use air or inert gas under pressure (DO NOT USE
OXYGEN).
■ ■ ■ ■ Before gas is turned into the system, a
check must be made to see that there
are no open fittings and to make sure
the burner main manual valve and pilot
manual valve are closed. Purge the gas
line up to the burner inlet. Discharge
purged gas outside of the building, do
not purge into the combustion chamber.
Each burner is supplied with an individual initial start-up procedure. The start-up
instructions number for your burner is listed on the front cover of this manual.
■ ■ ■ ■ After the initial start-up procedure the following steps can be followed for routine start-up and
shut-down on a seasonal basis.
Extended Burner Shut-Down
1.
Turn off burner switch.
2. Close main manual valve.
3. Close pilot manual valve.
4. Turn off line switch.
Burner Start-Up
1.
Make sure line switch and burner switch are off.
2. Set controller to call for heat.
3. Open firing door.
4. Open main and pilot manual gas valves.
5. Depress flame safeguard reset button.
6. Reset low gas pressure switch (if used).
7. Turn on line switch.
8. Turn on burner switch and allow burner to run through firing cycle.
9. Close firing door.
10. Reset controller to desired setting.
Table 5: Recommended Gas Piping
* Multiplier for Propane: 1.57
** Multiplier for alternate pressure drops: 0.3" W.C.-.77,
1.0" W.C.-1.40, 2.0" W.C.-2.00, 4.0" W.C.-2.80.
Feet
From
Meter
1 1 /
4
" 1 1 /
2
" 2" 3" 4" 2 1 /
2
"
Maximum Capacity for Natural Gas*
MBTU/hr. Based on 0.5" W.C. Pressure Drop**
Pipe Size
25
40
60
80
100
125
150
175
200
760
660 1175
1000
810
690
620
2375
1900
1520
1300
1150
1020
950
850
800
3900
3000
2400
2050
1850
1650
1500
1370
1280 6000
5300
4300
3700
3250
2950
2650
2450
2280
5500
5000
4600
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