Installation & Operation Manual
High and low gas pressure switches
(continued)
Venting of gas train components - and optional
gas train components
Local codes may require the routing component bleeds and
vents to the atmosphere outside the building. Components
(valves, pressure switches) having vents which would require
external vent lines are provided with threaded vent line
connections. These vent line connection points may be accessed
by removing the top jacket panels. Proper routing of vent lines
to the atmosphere from the factory supplied termination
points is the responsibility of the installing contractor.
GAS
VALVE
BALL VALVE
W/PRESSURE TAP
GAS COCK
LOW
PRESSURE
SWITCH
HIGH
PRESSURE
SWITCH
ALUMINUM
TUBING
.25 X .03
*SEE REGULATOR
INSTALLATION
NOTE ON PAGE 33
ROUTING MAY VARY
TYPICAL PRESSURE REGULATOR
STYLE MAY VARY FROM SHOWN
“FIELD PROVIDED”
(IF REQUIRED BY LOCAL CODES)
TYPICAL SHUTOFF
VALVE
“FIELD PROVIDED”
(IF REQUIRED BY LOCAL CODES)
GAS VALVE
ALUMINUM
TUBING
.25 X .03
BALL VALVE
BALL VALVE
W/PRESSURE TAP
TYPICAL PRESSURE REGULATOR
STYLE MAY VARY FROM SHOWN
“FIELD PROVIDED”
(IF REQUIRED BY LOCAL CODES)
*SEE REGULATOR
INSTALLATION
NOTE ON PAGE 33
ROUTING MAY VARY
LOW
PRESSURE
SWITCH
HIGH
PRESSURE
SWITCH
TYPICAL SHUTOFF
VALVE
“FIELD PROVIDED”
(IF REQUIRED BY LOCAL CODES)
Figure 3-3A_VF 500 - 1000 High & Low Gas Pressure
Switches
Figure 3-3B_VF 1500 - 2000 High & Low Gas Pressure
Switches
NOTICE
The gas train and controls assembly provided
on this unit have been tested under the
applicable American National Standard to
meet minimum safety and performance
criteria such as safe lighting, combustion,
and safety shutdown operation.
VF Series gas train
The ratio gas valve on this appliance uses line (120 VAC)
voltage for operation. The valve contains the safety shutoff
and operating valves required on water heaters. The ratio
valve uses the negative pressure signal generated by the
venturi to modulate the amount of gas, so that the proper
mixture of air and gas is delivered to the burner throughout
the full range of burner operation. The ratio gas valve does not
require installation of a vent line - see the
Venting of Gas Train
Components
section below.
There are no serviceable parts on the combination gas valve.
DOWNSTREAM
TEST VALVE
MANUAL SHUTOFF VALVE
VENTURI
RATIO VALVE
Figure 3-4_Gas Train Assembly VF 1500 - 2000
3
Gas connections
30
