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3. PIPING & CONTROLS
PIPING & CONTROLS
A. BOILER SUPPLY AND RETURN
1. See Figure 3.1 for suggested piping to the boiler.
2. Make up cold water supply connection to the boiler.
3. Plug all open tappings in the boiler and fill with
water. Apply approximately thirty (30) psi pressure.
Check to make certain that all joints and fittings are
water tight.
4. After all joints and connections have been proven
water tight, remove cold water supply and plugs
from all tappings that are to be used. See Figure 8.1
for tapping locations.
5. Return piping must allow for opening and closing
Burner Mounting Plate. PB Heat, LLC suggests
installing a 1-1/4 NPT tee, a 90° elbow, and a 1-1/4
NPT x 5” long nipple in the return tapping before a
vertical stand pipe is used.
6. The supply and return connections should be sized
to suit the system. A 1-1/2” to 1-1/4” reducing
coupling may be used on the return where the
system piping is 1-1/2”.
7. The supply should be out of the top of the back
section and return to the bottom of the front section.
There is a 3/4” tapping in the top of the back section
for air elimination.
8. When the return temperature from the system will
be below 150°F on oil boilers for extended periods
(heat pump systems, outdoor reset, snow melt, etc.),
provide piping and controls to protect the boiler
from condensation. Condensation will damage the
boiler and will lead to shortened boiler life and
maintenance problems.
9. If the boiler is to be used in conjunction with a
refrigeration system, the chilled medium shall be
piped in parallel with boiler and proper valves
applied to prevent the chilled medium from entering
the boiler. Refer to Figure 3.2.
10. If the boiler is connected to heating coils located in
air handling units, the boiler piping system must be
equipped with flow control valves or other automatic
devices to prevent gravity circulation of the boiler
water during the cooling cycle.
B. SAFETY RELIEF VALVE
1. Remove safety relief valve and 3/4” x 3” nipple from
parts bag. Install nipple and safety relief valve in top
or rear tapping. See Figure 8.1. If rear tapping is
used, installer must supply an elbow so that safety
relief valve is installed in vertical position.
C. TANKLESS WATER HEATER
Figure 3.1
CHILLER
VALVE
SUPPLY LINE
CHECK VALVE
BOILER
WATER
THREE WAY
RETURN
LINE
Figure 3.2
Install mixing valve in hot water supply piping. Water
temperature above 125°F can cause severe burns
instantly or death from scalds.
DANGER
Install anti-scald device in hot water supply piping.
Water temperature above 125°F can cause severe
burns instantly or death from scalds.
DANGER
Pipe the discharge of the safety relief valve to
prevent injury in the event of pressure relief. Pipe the
discharge to a drain. Provide piping that is the same
size as the relief valve.
CAUTION
