2
POINT OF CONNECTION
A. General
The Series B and Series D tanks work equally well when installed in the
vertical or horizontal position. When Series B tank is installed horizontally,
the system connection must be located below the centerline of the tank.
The Series B-LA tanks must be installed in vertical position. They cannot
be installed in the horizontal position.
The pressurized expansion tank-to-system piping differs from the
“standard” compression tank piping in several major aspects:
1. Air from the system must be purged to the atmosphere and not allowed
to enter the tank.
2. Tank-to-system piping must not be pitched-up to the tank.
3. Shut-off and drain valves or tank purge valve B&G TPV must be
installed in the tank-to-system piping in order to properly check and
recharge the tank air after the system has been filled with water.
4. Airtrol Tank Fitting (ATF or ATFL) is not required.
B. Piping
Typical tank-to-system and air vent piping are illustrated by Figures 1 thru
6. Some general notes regarding this piping are listed below:
1. The connection point from tank-to-system represents the point of no
pressure change. This means that the expansion tank must be
connected as close as possible to the suction side of the system
circulating pump for proper system operation.
2. The branch piping to the tank must be attached to the main to minimize
the possibility of air and debris entering the tank piping. If connected
to the horizontal main, do not use top (12 o'clock) and bottom (6 o'clock)
positions. Side connections are the proper positions. If connection
must be made at the bottom, a dirt trap leg with a flushing drain valve,
such as shown in Figure 4, should be installed.
3. Table A shows the recommended pipe sizes. Note that the MBH
column represents the output of the heat generator (firing rate, etc.).
The pipe sizes are selected for very low pressure loss in the tank-to-
system piping to accommodate system operating pressures within
10% of the relief valve setting. However, if the actual system operating
pressure is less than 80% of the relief valve setting, the tabulated pipe
size above 1" may be reduced by one size.
Pipe sizes 1" or less must not be changed due to the greater possibility
of fouling in the smaller pipes.
4. In order to change the tank air charge pressure it is necessary to isolate
the tank circuit from the main system piping. A high quality, gate type
or TPV, lock-shield valve must be used for this purpose. The lock-
shield for the valve stem will eliminate tampering of this normally open
valve during normal system operation.
5. In addition to the lock-shield valve above TPV or a drain valve,
automatic air vent and a pressure gauge must be installed in the piping.
The drain valve is used for flushing (item 2 above) and to drain the
water out of the tank for proper air charging.
6. Tank sizing calculations are based on minimum temperature rise of the
air in the tank. For this reason, an anti-thermosyphon loop must be
formed in the tank-to-system piping to minimize the effects of gravity
(thermal) circulation into the tank. A drop leg from 12" to 20" long is
usually sufficient. It is also suggested that this piping and tank not be
insulated (heating systems only).
7. Allow an overhead clearance for the Series B of at least 36" to remove
the bladder through the flanged opening in case replacement is
required. For bladder replacement of the Series B-LA tanks, the tank
must be removed from the system.
INSTALLATION
1. Note location of system connection, air charge valve and drain
connection on tank.
2. Remove the plug or pipe cap from the system connection.
3. Remove the cap covering .302-.33" (standard tire valve) the air charge
valve.
4. Before making any connection to the tank, check the tank and air
charge (use an accurate pressure gauge). The air pressure must be
equal to the minimum system pressure at the tank location.
5. After making sure the air charge is correct, replace the cap over
the .302-.33" (standard tire valve).
6. The tank may now be piped to the system (use the suggested tank
piping diagram on page 4 and 5).
7. Using table A, select appropriate pipe size. Connection to each tank
must have a lock shield gate valve or TPV and union to allow isolation
and removal if required. Make up and fill valves, whether manual or
automatic, should be tied into the connecting line. This will ensure that
pump operation will not affect valve operation.
CAUTION: Pump cavitation and unbalanced circuits can result
from improper tank location. Connect tank as close to suction
side of system circulating pump as possible. Failure to follow this
instruction could result in property damage and/or moderate personal
injury.
WARNING: This product must be installed by a qualified
professional. Failure to follow the instruction in accompanying
manual may cause a rupture or explosion which may result in serious
injury or death and property damage.
WARNING: CALIFORNIA PROPOSITION 65 WARNING!
This product contains a chemical known by the State of
California to cause cancer and to cause birth defects or other
reproductive harm. (California Installer/Contractor – California law
requires that this notice be given to consumer/end user of this product.
CAUTION: A blocked connection to the expansion tank will
cause system to become overpressurized resulting in periodic
discharge of system relief valve. This periodic discharge will require that
fresh water be added to the system to maintain pressure. The resulting
addition of fresh water will cause corrosion in system components. The
use of a bottom connection to the main requires the use of dirt trap leg
with a flushing drain valve. Failure to follow these instructions could
result in property damage and/or moderate personal injury.
WARNING: System overpressurization will result if expansion
tank isolation valve is not kept open during normal operation.
Provisions must be made to lock this valve open during normal system
operation. Failure to follow these instructions could result in serious
personal injury or death and property damage.
WARNING: Do not locate this product where leaking or flood
could cause damage to the surrounding property. A drip pan
connected to an adequate drain must be installed if leaking or flooding
could cause property damage. Failure to follow this instruction could
result in property damage.
CAUTION: Lack of or improperly sized air vent will cause
system circulation problems. An automatic air vent must be
installed in the line to the expansion tank and at air separating devices
as shown in Figures 1 thru 6. These must be sized to vent off any
accumulated air. Failure to follow these instructions could result in
property damage and/or moderate personal injury.