Sterling GP Series - Manual (Page 17)

GP Series Portable Chillers Chapter 3: Installation 17 of 44
3-9 Water Reservoir
All portable chillers shipped during the fall, winter, or spring, or those units that are shipped
from stock are flushed at the factory with a water/ethylene glycol solution to prevent piping
components prone to retaining water from freezing. During startup and when additional
solution is required, refer to the ethylene glycol and propylene glycol curves in Figure 6 on
page 20 Add a pre-mixed solution of industrial quality (not automotive) ethylene glycol or
propylene glycol and water to provide freeze protection to a temperature 20ºF (11ºC) below
the normal chiller operating temperature set point.
Glycol and/or water, with an inhibitor, should be used to protect the materials (copper, steel,
stainless steel, and bronze) in the system from corrosion. If you intend to use straight water,
we strongly advise a minimum leaving water temperature of
45 ºF ( 7 ºC) or contact the service
department.
The following glycol products are available:
Part Number Description
A0541358 Ethylene glycol, 5 gallons (18.9 liters)
A0539637 Ethylene glycol, 55 gallons (208.2 liters)
A0542990 Propylene glycol, 5 gallons (18.9 liters)
A0542991 Propylene glycol, 55 gallons (208.2 liters)
Caution! Do not connect make-up water directly to the chilled water reservoir unless you
have an approved automatic water make-up system installed.
Caution! Do not pressurize tank. Supply and return connections must be trapped and
vented to allow vertical risers to drain into tank. Do not overfill system. Allow
enough free space in tank for vertical piping to drain.
If your application has chilled water or process piping above the reservoir fill and vent level,
trap and vent the supply and return lines to allow vertical piping to drain into tank.
Note: In applications where the process or process piping is above the reservoir, take
steps to prevent over pressurization of the reservoir. This condition can occur
on system shutdown when the water in the system drains into the reservoir. To
prevent this, a vacuum breaker should be installed at the high point of the “To
Process” and “From Process” lines.