LAARS Pennant PNCV (Sizes 500-2000) - Install and Operating Manual - Manual (Page 16)

LAARS Heating Systems Page 16
PRIMARY/SECONDARY MANDITORY FOR ALL
VARIABLE FLOW SYSTEMS
INSTALL AIR VENTS AT HIGH POINTS IN SYSTEM
PIPING & SIZING OF EXPANSION TANK
PER TANK MANUFACTURER'S INSTRUCTIONS
DIMENSION "C" (COMMON PIPING) TO BE FOUR
PIPE DIAMETERS, MAX. (NO ELBOWS OR VALVES)
BOILER CIRCUIT PIPING MUST BE EQUAL
TO BOILER WATER CONNECTION SIZE
BOILER CIRC. PUMP SIZED FOR FLOW THROUGH BOILER
DOTTED DEVICES INDICATE ALTERNATE LOCATIONS
PUT BOILER CONTROL SENSOR IN THE SYSTEM
C
PUMP LOCATION FOR PUMP-MOUNTED UNITS
SYSTEM PUMP
MAKE-UP
COLD WATER
SUPPLY
SYSTEM
PUMP LOCATION FOR
NON-PUMP-MOUNTED UNITS
RETURN
SYSTEM
SUPPLY WHEN USING THIS PIPING STYLE.
MINIMUM BOILER INLET WATER TEMPERATURE
MUST BE AT LEAST 120°F.
C
ADJUSTMENT PROCEDURE TO MAINTAIN
120°F INLET TEMP:
1. Turn on boiler and open valves A & B.
2. After steady-state operation, if T1 is less than
slowly close valve B until T1 climbs to
120°F.
3. If T1 is greater than 120°F, slowly close
until T1 drops to 120°F.
4. Check after system operating temperature
has stabilized. Make final adjustments.
120°F,
valve A
A
B
T1
B
A
T1
LEGEND
CHECK VALVE
THERMOMETER
TEMPERATURE
SENSOR
GLOBE VALVE
EXPANSION TANK
WITH AIR SCOOP AND
AUTO AIR VENT
3-WAY VALVE
VALVE
CAUTION: THIS DRAWING SHOWS SUGGESTED
PIPING CONFIGURATION AND VALVING, CHECK
WITH LOCAL CODES AND ORDINANCES FOR
ADDITIONAL REQUIREMENTS.
PRESSURE REDUCING VALVE
W/ FAST FILL BYPASS
PURGE
VALVE
PUMP
Figure 5. Hydronic Piping — Multiple Boilers, Low Temperature System.