Patterson-Kelley TBIG-03 - Manual (Page 14)

Gemini™ Twin-Fuel Gas-Fired Boiler
natural gas
connection (2")
and shutoff
propane
connection (1 1/4")
and shutoff
main gas valve
propane
gas valve
natural gas
gas valve
pilot gas
supply
high gas pressure
switch
propane regulator
natural gas
regulator
secondary
shutoff
water
connection
low pressure
switches
(visible from side)
pressure tap
mechanical link
to air control
auxiliary panel
(service power shutoff
switch inside)
auxiliary panel
(service power shutoff
switch inside)
propane low
pressure
switch
pressure tap
secondary
shutoff
high gas
pressure
switch
main gas
valve
propane
connection (1")
and shutoff
propane
gas valve
natural gas low
pressure switch
water
connection
natural gas
gas valve
natural gas regulator
pilot gas supply
natural gas
connection (1 1/4")
and shutoff
Figure 5-1 Twin-Fuel Gas Train
(Top photo shows 1500/1700/1900 series; bottom shows 700/900/1200 series)
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