Key To System Schematics - Eclipse ExtensoHeat EH050 Installation Manual

Key to System Schematics

Symbol Appearance
Main Gas
Shut-Off
Valve Train
P
NC
M
Name
ExtensoHeat Burner
Main Gas Shut-Off Valve Train
Combustion Air Blower
Air Pressure Switch
Gas Cock
Solenoid Valve (Normally Closed)
Manual Butterfly Valve
Automatic Butterfly Valve
Motorized Gas Control Valve
Adjustable Limiting Orifice
Pressure Taps
Remarks
Eclipse strongly endorses NFPA
as a minimum
The combustion air blower
provides the combustion air
pressure to the burner(s)
The air pressure switch gives a
signal to the safety system when
there is not enough air pressure
from the blower
Gas cocks are used to manually
shut off the gas supply on both
sides of the main gas shut-off
valve train
Solenoid valves are used to
automatically shut off the gas
supply on a bypass gas system or
on small capacity burner systems
Manual butterfly valve are used to
balance the air or gas flow at each
burner, and/or to control the zone
flow
Automatic butterfly valves are
typically used to set the output of
the system
A motorized gas control valve
adjusts the gas flow to the
burner(s) based on the control
system requirements
Adjustable limiting orifices are
used for fine adjustment of gas
flow
The schematics show the advised
positions of the pressure taps
Bulletin/
Info Guide
235
756
610
610
710
760
720
728/730
ii