Non-Pressurized Flow Centers - Bosch Geothermal Heat Pumps Applications Manual

Applications Manual Bosch Geothermal Heat Pumps | 93

14.3 Non-Pressurized Flow Centers

Non-pressurized ow centers (Fig. 107) are simply
canisters that hold uid on the suction side of circulating
pumps (one, two or three) and include built-in pump
protection which eliminates the need for a " ush cart"
when manifolds are indoors. Flush carts will be discussed
in the ushing and purging section.
These non-pressurized ow centers allow the force of
gravity to maintain a ooded volute within the device,
assuring reliable pump operation. This type of ow center
pumps uid to the geothermal heat pump, and then out
to the ground heat exchanger, and then returns the uid
directly back to the ow center.
Non-pressurized ow centers allow any entrapped air
within the system to remove itself over time. Also, the
circulating uid level and freeze protection level can easily
Fig. 107 Non-pressurized ow center
be monitored and replenished as necessary. These ow
centers can directly measure system ow and typically
come equipped with check valves and pump isolation
valves. Additionally, a ush cart is not necessary to ll and
ush the system when a non-pressurized ow center is
utilized.
However, these non-pressurized ow centers require
a manifold be assembled for the lling and ushing
process. A typical example is shown (Fig. 108). Also, the
highest point of the piping system cannot be more that
approximately 34 feet above the circulating pump or
pumps.
Fig. 108
Bosch Thermotechnology Corp.
Data subject to change