Smith 8 series Installation And Operating Instructions Manual page 6

Page 6
PIPING
Pumped Bypass
For these systems that may experience condensation,
an additional circulator and balancing valve can be
used to provide a return water temperature blend. This
method works well with systems with multiple zones
with circulators, see Figure 5. The dedicated bypass
circulator provides a strong blending flow without
diminishing the fl ow available to any heating zone. Any
residentially sized circulator is adequate for this purpose.
The balancing valve allows for adjustment of the return
temperature (see adjustments procedure in Figure 5).
Figure No. 5 – Pumped Bypass
Backflow-Prevention
Drain Cock
Device
8 SERIES BOILER INSTALLATION AND OPERATING INSTRUCTIONS
Air Vent &
Expansion Aquastat
Thermometer
Separator
Tan k
Pump Away Bypass
For systems that use a single circulator to pump away
from the boiler, the bypass should be installed on the
discharge side of the circulator, see Figure 6. Full
temperature water supplies the baseboard distribution
system as before. Half of the circulator's volume moves
through the bypass, blending and heating the cooler
return water. Again, the cost of installing the bypass is
small and setting it by temperature can be accomplished
with a contact thermometer (see bypass adjustment
procedure Figure 6).
1. Close valve A and C.
2. Attach a short hose to valve D and submerge in bucket
of water. Open Valve D.
3. Manually open the fill valve and use the domestic water
system pressure to purge air from each zone one at a
time. When air bubbles stop flowing from the hose
close valve D.
4. Rest fill valve to automatic fill, and open valves A and C.
Bypass Adjustment Procedure To Maintain Inlet
1. Turn boiler on and close valve A.
2. After steady-state operation, if T1 is less than 130° F
slowly open valve A until T1 climbs to desired operating
temperature above 130° F.
3. Check after system operating temperature has
stabilized. Make final adjustments.
NOTES:
1. Boiler circuit piping must be sized large enough to handle
maximum flow through unit.
2. Boiler pump sized to boiler design flow requirements.
3. All boilers furnished with factory mounted water
temperature/pressuregauge.
4. A plug valve will allow the best flow control for the bypass.
A ball valve may not be suitable and may create noise.
Notice: These drawings show suggested piping configuration
and valving. Check with local codes and ordinances for
specific requirements.
Pressure Pressure
Check Valve
Relief Valve Reducing Valve
System Purging.
Te mperature Above Dew Point
T1=Te mp Min=130° F
Ball or Gate
Pump
Balance Valve
Valve