31
IOM, BS/BT Models
Enertech Global
Flushing & Charging a Pressurized Flow
Center
Once piping is completed between the unit,
flow center, and the earth loop, final purging
and charging of the system is needed. A flush
cart (at least a minimum of 1.5 hp pump motor
or larger) is needed to achieve adequate flow
velocity (2 fps in all piping) in the loop to purge
air and debris from the loop piping (unless the
header manifold is located inside and has
isolation valves). All air and debris must be
removed from the system before operation
or pump failure could result. The flush ports
located on the flow center are access to the
piping system for the flush cart. See figure 7 for
connection details.
The 3-way valves on the flow center include
direction indicators on the valves which
determine the flow path (see figure 8). A 3/8”
socket drive is required to operate the 3-way
valves. The valves will turn in either direction,
360 degrees. Make sure during this process that
the valves are in the same position so that air
does not become trapped in the system.
Water Quality
Even on a closed loop system water quality
is an issue. The system needs to be filled with
clean water. If the water on site has high iron
content, high hardness, or the PH is out of
balance, premature pump failure may result.
Depending upon water quality, it may need to
be brought in from off site.
Removing Debris During Flushing
Most flow center or pump failures are a
result of poor water quality or debris. Debris
entering the loop during fusion and installation
can cause noise and premature pump
failure. Enertech recommends a double
flush filtering method during purging. When
purging, use a 100 micron bag filter until
air bubbles are removed. Remove the 100
micron bag, replace it with a 1 micron bag
and restart the flushing.
Flush Cart Design
The Enertech Manufacturing flush cart has been
designed to effectively and efficiently flush the
earth loop and to facilitate injecting and mixing
of the antifreeze. The single most important
element in flow center reliability is the ability to
remove all the air and debris from the loop and
to provide the proper working pressure.
Features of the flush cart:
•
Cylinder: HDPE, SDR15.5, 10” dia. (10 Gallons)
•
Pump: Myers High Head QP15, 1.5hp, 115V
•
Hose connections: Cam Lock quick connects -
1-1/2” hoses
•
Hand Truck: 600lb rating with pneumatic tires
•
Wiring: Liquid Tight metal on/off switch
•
Tubing: SDR11 HDPE
•
Connections: 2 - 3/4” connections for antifreeze
and discharge
•
Drain: one on the pump and the tank
Section 6: Unit Piping Installation
Step 1: Flushing the Earth Loop
•
Connect flush cart hoses to flow center flush
ports using proper adapters #AGAFP.
•
Connect water supply to hose connection on
return line of flush cart.
•
Turn both 3-way valves on flow center to flush
ports and loop position.
•
Turn on water supply (make sure water is of
proper quality).
Figure 16: Enertech Manufacturing Flush
Cart