17
Installation and operation manual
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DTHR-V9-2020
Gas train
1
Pilot solenoid valve and gas regulator
2
Pilot manual gas valve
3
Main manual valve (by other outside the unit)
4
Test port inlet pressure
5
Main gas regulator
6
Main gas safety shutoff valve 1
7
Valve proving system (with IRI option)
8
Main gas safety shutoff valve 2
9
Modulating gas valve actuator
10
Modulating gas valve
11
Low fire orifice bypass
12
Test firing gas valve
13
High gas pressure switch (FM and IRI option)
14
Test port manifold pressure
15
Main gas orifice (some models, various sizes)
16
Burner box
17
Air orifice plate (some models, various sizes)
18
Burner air blower
19
Low gas pressure switch (FM and IRI option)
