Introduction
1-10
IC-SA-1511 (02/2014)
V/LNV Series Manual
valve. Safety shutoff gas valves are wired into the programming control to automatically open and close at
the proper time in the operating sequence.
1.7.1 — Main Gas Train Components
Depending upon the requirements of the regulating authority, the gas control system and gas train may
consist of some, or all, of the following items:
Main Gas Train
Component
Description
Gas Volume Valve
The butterfly type valve is positioned by linkage from the modulating motor and
controls the gas flow rate.
Main Gas Valves
Electrically operated safety shutoff valve(s) that open to admit gas to the burner.low
fire Standard UL burners include:
•
Models V13-25: diaphragm gas valve & solenoid valve
•
Models V30-50: one (1) motorized gas valve w/proof of closure or two (2) safety
shutoff valves
•
Models V55-120: one (1) motorized gas valve w/proof of closure and one (1)
safety shutoff valve
•
Models V126-168: two (2) motorized gas valves
(two motorized gas valves can be optionally provided on all models)
Main Gas Regulator
Regulates gas train pressure to specified pressure required at the burner manifold.
Input is set by main gas pressure regulator adjustment.
Main Gas Cocks
Used for manual shutoff of the gas supply upstream of the pressure regulator. A
second shutoff cock downstream of the main gas valve(s) provides a means of
testing for leakage through the gas valve(s).
High Gas Pressure Switch
(Models V30-168)
A pressure actuated switch that remains closed when gas pressure is below a
selected setting. Should the pressure rise above the setting, the switch contacts will
open causing the main gas valve(s) to close. This switch requires manual reset after
being tripped.
Low Gas Pressure Switch
(Models V30-168)
A pressure actuated switch that remains closed when gas pressure is above a
selected setting. Should the pressure drop below this setting, the switch contacts
will open, causing main gas valve(s) to close. This switch requires manual reset after
being tripped.
NOTE:
The pilot gas supply connection must be upstream of the main gas pressure regulator.
NOTE:
Gas train components upstream of the butterfly valve are shipped loose and are to be mounted by the
installer. If a pre-piped and wired gas train is ordered, the components upstream of the first safety shut-off valve
are shipped loose and must be mounted by the installer.