2
BOILER
FF
EXPANSION
TANK
ZONE 1
ZONE 2
V1
PV4
FIGURE 1:
PREFERRED PIPING
FOR CIRCULATORS
ON BOILER SUPPLY
ZONE 1
V2
V3
P
ZONE 3
ZONE 2
V2
V3
P
ZONE 3
V2
V3
P
• AIR PURGING SEQUENCE
BY ZONE
LAST
FIRST
BOILER
FF
EXPANSION
TANK
ZONE
1
ZONE
2
V1
PV4
ALTERNATE PIPING
FOR CIRCULATORS
ON BOILER RETURN
ZONE 1
ZONE 2
V2
V2
V3
V3
P
P
ZONE
3
ZONE 3
V2
V3
P
• AIR PURGING
SEQUENCE
BY ZONE
LAST
FIRST
KEY:
VI, V2, V3 = SHUT-OFF ISOLATION VALVE
P = TACO CIRCULATOR WITH IFC
FF = FAST FILL BOILER FEED VALVE
PV4 = PURGE VALVE
RECOMMENDED PURGING STEPS:
1. CLOSE V1, PV4, V2
2. OPEN V3
3. OPEN FF VALVE
4. OPEN V2, PV4, TO PURGE LAST ZONE
FIRST (ZONE 3)
5. CLOSE FF VALVE
6. CLOSE V2, PV4
7. REPEAT STEPS 1 TO 6 FOR EACH
ADDITIONAL ZONE, PURGE ZONE 1 LAST
8. OPEN V1 WHEN ALL ZONES ARE
PURGED
9. ADJUST SYSTEM TO DESIRED OPERATING
FILL PRESSURE IF REQUIRED
