Patterson-Kelley TBIG-03 - Manual (Page 7)

Installation
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propane
connection
manual
shutoff
natural gas
connection
manual
shutoff
regulator
low gas
pressure switch
motorized gas valve
(propane)
low gas
pressure switch
motorized gas valve
motorized gas valve
(natural gas)
high gas pressure
switch
pressure tap
burner
secondary
shutoff, manual
pilot
shutoff
regulator
pilot regulator and
solenoid valve
mechanical link
to control air
(Lo-Hi-Lo only)
Items with symbol must be
vented to outside. Refer to the
drawings packed with your
boiler for additional information.
leak test
valves
n.o. vent valve
(I.R.I. only)
Figure 4-1 Piping Schematic for the Twin-Fuel Gas Train
4.0 I
NSTALLATION
Gas Train Connection Sizes
Natural Gas Propane
700/1000/1200
Series
1 1/4" 1"
1500/1700/2000
Series
2" 1 1/4"
4.1 G
ENERAL
Installation of the twin-fuel Gemini™ boiler is similar
to that of the single-fuel model. Refer to “Thermific
â
Gas-Fired Boiler - Installation and Owner’s Manual -
TBIG” pages 2 through 10.
The following procedures are different from those for
the single-fuel model, and are described in this Sec-
tion:
· Gas Piping
Gas Bleeds and Vents
· Pre-Start Check List
· Pre-Start Safety Checks and Adjustments
Test of Ignition Safety System
Test of Low Water Cutoff
Test of High Limit Control
Test of Gas Pressure Switch
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