Webster JB Series Installation, Startup, Operation And Maintenance Manual page 23

3. Gas Systems
Illustrated Gas Trains by Capacity and Code: The following illustrations show the Webster confi guration for UL,
FM and IRI as grouped by UL capacity ratings. Refer to the legend below for component part identifi cation. These
illustrations are not to be used for fi eld erection and/or system design purposes.
UL Capacity Range
BTU/Hr.
To 2,500,000
2,500,001
to
5,000,000
5,000,001
to 12,500,000
12,500,001
and Up
NOTE: Pressure Drops; Pressure drop through a given gas train will vary somewhat in relation to the individual items
used, the specifi c gravity of the gas to be burned and the overall length.
722091
Field Piped
Pilot Manual
Ball Valve
Manual Ball
Valve
Gas
Supply
UL-FM On-Off Gas Piping Diagram - Up to 2,500 MBH Firing Rate 1/2 PSI Max
JB Manual
Operation Mode
On-Off
Low Fire Start
Low Hi Low
Modulating
Low Fire Start
Low Fire Start
Low Hi Low
Low Hi Low
Modulating
Modulation
Modulating
Modulating
Modulating
Modulating
Pilot Gas
Pilot Solenoid
Pressure
Valve
Regulator
Vent To Outside
Atmosphere
Main Solenoid
Gas Valve
S
Gas Pressure
Manual
Regulator
Test Valve
Webster
Designation
UL / GE
GAP
A X
L X
H X
M X
L X
L
H X
H
M X
M
M X
M
M X
M
S
Main Diaphragm
Gas Valve
Manual Ball
D Valve
Field Piped
Manual Test
Valve
Page 23
Code Illustration
FM
X 722091
X 722001
X 722022
X 722003
722002
X 722009
722023
X 722024
722004
X 722010
722005
X 722011
722082
X 722084
Test
Connection
Gas Pilot
Ignitor
Gas Burner
Manifold
722091
Fuel Systems