12
Table 6 – Piping Water Volumes
PIPE SIZE
COPPER PIPE FACTOR
STEEL PIPE FACTOR
1/2---IN.
82.5
63.5
3/4---IN.
40.0
36.0
1---IN.
23.3
22.2
1---1/4---IN.
15.3
12.8
1---1/2---IN.
10.8
9.5
2---IN.
6.2
5.8
---Divide total length of piping in feet by appropriate factor in table to de-
termine volume in gallons.
An air purger is used to remove air from system. It is installed in
supply line. It eliminates air from water before it reaches radiators
and bleeds off this air.
E. Main
Air
Vent
for
Downflow
Systems
or
Diaphragm--Type Expansion Tank (Not Provided)
Before a system is filled with water, there is air in pipes and
radiation units. Some of it will be trapped as system fills. It is
possible to eliminate most of this air through air vents on
radiation units. A main air vent speeds and simplifies this process.
It should be installed on highest point in supply main when all
radiation is below top of boiler.
F. Aquastat Relay Control (Provided)
The water temperature limit control in aquastat relay is adjustable
and may be set as necessary. It may be set as low as 140
_
F or as
high as 240
_
F. This depends on type and amount of radiation
involved and weather conditions.
G. Automatic Fill Valve (Not Provided)
For safe, efficient operation, a hot water system must be filled
with water. Adding new water when needed can be done
manually (by use of a hand valve in water supply line). This
requires regular attention to system’s needs. An automatic fill
valve accomplishes this without attention. It is installed in supply
line on hot water boilers only. The valve operates through water
pressure differentials. It does not require electrical connection.
H. Drain Valve (Provided)
This manual valve provides a means of draining all water from
boiler and system. It is installed in a tee where return line enters
boiler.
I. Circulating Pump (Provided)
Every forced hot water system requires a circulating pump. A
separate pump or zone valve is required for each zone if there are
2 or more zones. The circulator must have the capacity to provide
the circulation required by the heating system. The circulator
should be connected to the supply main and must be wired into
the boiler’s electrical system. See the prior pages of installation
section for piping configurations with the circulator located on
the supply main piping using zone circulators or zone valves.
When the piping is arranged with zone circulators and no bypass
piping, the circulator provided with the boiler may be used as a
zone circulator. Both piping arrangements allow the circulator to
pump away from the expansion tank and show how the piping
should be arranged to allow the heating system to be easily
purged of air.
J. Oil Solenoid Valve
The Beckett oil burner uses a standard solenoid valve. Upon
burner shutdown, a standard solenoid valve stops the flow of oil
to the nozzle. Without the solenoid valve, the oil pump continues
to pump oil to the burner nozzle until the motor winds down
below the pump cut--off speed. The Riello oil burner has a delay
oil solenoid valve. The delay solenoid valve provides the same
shut down action of the standard solenoid valve, plus on burner
start--up, the delay solenoid valve remains closed for an
additional 15 seconds. This allows the burner fan motor to
pre--purge the combustion chamber and the oil pump to bring the
supply oil pressure up to its set point helping to provide a clean
light off.
Filling Boiler
OPTION #1
A. How a Hot Water System Operates
The entire heating system (boiler, piping, and radiation units) is
filled with water. As water in boiler is heated, it is pumped from
top of boiler through supply main to radiation units. The cooler
water in them flows back through return main to boiler. This
provides positive and rapid response to thermostat.
B. Filling System With Water
a. Close the main shutoff valve, isolation valves, and
zone valves (if applicable). If bypass piping is
installed, also close the two throttling valves. Leave
the boiler service shutoff valve (if installed) and the
balancing valves to each heating zone fully open.
b. Open the following valves in order: the drain valve for
power purging, isolating valves before and after the
boiler circulator (if applicable), both throttling valves
(if applicable), and then open the fill line shutoff
valve. Water will fill the bypass piping and push air
through the piping and out the power purging drain
valve. When the power purging drain valve runs air
free, close the bypass throttling valve (leaving the
throttling valve to the supply piping fully open)
c. Next, open the isolation valve (or zone valve) to the
first zone. Water will fill the piping and push any air
out the power purging drain valve. When the power
purging drain valve runs air free, close the isolation
valve or zone valve. Repeat this procedure for the
remaining heating zones.
d. Once all of the zones are filled with water and purged
of air, close the power purging drain valve and fill line
shut off valve, open the main shutoff valve, and adjust
the throttling valves and balancing valves as required.
OPTION #2
1. Close air vents on all radiation units. Open valves to these
units.
2. Make sure boiler and expansion tank drain cocks are
closed. The air bleed screw on tank drain fitting should be
closed.
3. Open valve in line from boiler to expansion tank.
4. Open water inlet to boiler and leave it open.
5. Start with the LOWEST radiation unit. Open the air vent
on this radiation unit. When all air has escaped and water
starts to flow from vent, close air vent.
6. Proceed to next lowest radiation unit and repeat process
outlined in item 5. Repeat until every radiation unit in
system has been covered. End with the highest unit in
system.
If units have automatic vents, this manual venting is unnecessary
but will speed up proper filling of system.
If system is a closed expansion tank system, there should be an
automatic fill valve. It may be left open to refill system
automatically as needed.
Check temperature--pressure gage. Note position of hand
indicating pressure. This should be between 10 and 15 psi. Any
lowering of this movable hand below 10 psi indicates loss of
water due to leakage. The automatic fill valve should compensate
for this. If it does not, manually open this valve to refill system
BW
4
/BW
5
