Brochure

122
Selection Guides
Hoffman Specialty
®
Selection Guidelines
Series 2000 Typical Applications (continued)
Self-Contained
Temperature
Pilot
Main
Valve A
Solenoid
Pilot
Main
Valve B
Solenoid
Pilot
Heat
Exchanger
To
Power
Source
Mixing
Tank
Aquastat
Y Strainer
Y Strainer
Y Strainer
Y Strainer
Water
System
F & T
Trap
Steam
Supply
Self-Contained
Temperature
Pilot
Cold
Water
F & T
Trap
Circulating Pump
Vacuum
Breaker
Heated
Water
Return
Circulating Pump
Main Valve
Check
Valve
Heated
Water
Air
Supply
Line
Feedback Line
Pneumatic
Temperature
Pilot
Steam
Inlet
Cold Water
Air PRV
Regulator
Air
Pilot
Instantaneous
Heater
Y Strainer
F&T
Trap
Y Strainer
Pneumatic Temperature Control on Instantaneous Heater
Temperature Regulators Used in Parallel to Control Widely Varying Flow Rates
Description: Air pilots provide the fastest response to rapid
changes in the system temperature. They are recommended
for instantaneous applications when control air is available.
Description: Two Series 2000 Main Valves,
each with a Self-Contained Temperature pilot
can be used
on widely varying loads. Normally
valve “A” is sized for 1/3 of the total load and
handles light duty. Valve B is sized for the
remaining 2/3 load and operates only during
heavy demand. This is accomplished by
staggering the set points.