Burnham ALP080 - Manual (Page 2)

2
B.
Piping System To Be Employed.
Alpine (ALP) boilers are designed to operate in a
closed loop pressurized system. Minimum pressure in
the boiler must be 12 PSI.
Maintaining the proper water flow rate through the
heat exchanger of the Alpine boiler is crucial to ensure
trouble-free operation and long life. In addition to
causing operational issues within the boiler, insufficient
water flow through the heat exchanger can cause
damage and contribute to premature failure of the
boiler. Excessive flow through the heat exchanger can
be just as problematic resulting in potential noise and
erosion.
NOTICE
Failure to maintain the flow through boiler within
specified limits could result in erratic operation or
premature boiler failure.
1. near boiler piping must isolate alP boiler from
system piping via closely spaced tees to insure
specified flow range through boiler any time the
boiler is firing:
a. The flow rate through the boiler heat exchanger
and near-boiler piping is maintained by factory
recommended and installer supplied boiler
circulator.
Factory recommended range of circulators
based on factors often found in most hydronic
systems and shown in Table 9 will generate
an adequate flow rate and match combined
pressure drop through boiler heat exchanger
and near-boiler piping.
Table 9 lists recommended near-boiler piping
pipe diameter and circulator model for each
Alpine boiler model based on 25°F DT through
heat exchanger and up to 75 equivalent feet
near-boiler piping length. These selections are
adequate for most normal boiler installations.
However, installations operating at different DT
or with near-boiler piping length in excess of 75
equivalent feet may require different circulator
selection.
In such instances, the boiler heat exchanger
proper flow and head loss for different DT
may be selected from either Table 10 or “Alpine
Boiler Head Loss vs. Flow” Chart.
Next, near-boiler piping pipe diameter must
be sized based on 2 to 5.5 ft./sec. velocity
range, and near-boiler piping total equivalent
length determined based on the piping layout
and fittings and valves used, selecting their
equivalent length values from Table 11.
Thereafter, boiler heat exchanger head loss
and near-boiler piping total equivalent length
must be added, and an adequate circulator
selected based on proper flow and combined
boiler heat exchanger head loss and near-boiler
piping total equivalent length.
b. The flow rate through the isolated boiler loop
is completely independent of the flow rate
through the heating system loop(s).
c. The flow rate through the heating system loop(s)
is controlled by installer sized/provided system
loop circulator(s).
d. This piping arrangement can be used in space
heating-only applications as well as space
heating with indirect water heater. See Figures
23A or 23B “ Near Boiler Piping – Heating
Only” and 24A or 24B “ Near Boiler Piping
– Heating Plus Indirect Water Heater”.