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GLYCOLS. Ethylene or propylene based glycols – May be
used with brazed plate heat exchangers. The glycol should be
tested annually, or more often if required, to be sure the fluid
still retains the desired properties and protection. No permanent
connection should be made between a system containing
ethylene glycol and a drinking water supply.
Automotive glycols – Not recommended; usage may result in
reduced thermal performance of the heat exchanger.
FREEZE PROTECTION. It is not recommended to cool water
below 33°F (0.6°C) due to the tolerances of the measuring
equipment. For freeze protection it is recommended to use
thermostats and/or temperature controls in the piping.
Low pressure Cutout – In water chiller applications, in
addition to the flow switch, the low pressure cutout on the
refrigerant side is the most important freeze protection control.
To prevent freeze damage and to protect the heat exchanger
and compressor, the low pressure cutout should be set no lower
than 28°F (–2°C), based on evaporator refrigerant pressure at
this temperature. If part-load or transient loads cause the chiller
to cycle off, use a resetting low pressure control with anti-
cycling timer or install a hot gas bypass control to maintain the
appropriate suction pressure at low loads.
NOTE: Use of a leaving chilled water sensor will not provide
adequate freeze protection.
SWIMMING POOLS AND SPAS. The use of chlorinating
devices requires that all chemical feeds MUST be downstream
from the heat exchanger, and a check valve should be installed
to prevent backflow of chemicals into the heat exchanger
whenever the pump is not in operation.
1081BP SERIES
CLEANING. In some applications the heat exchanger may be
subjected to severe fluid conditions, including high temperature
and/or hard water, causing accelerated scaling and corrosion
rates and reducing the performance of the heat exchanger.
Because of these factors, it is important to establish regular
cleaning schedules. Chemical cleaning is a very simple and
effective process for removal of fatty and calcium deposits
and other forms of scaling from brazed plate heat exchangers.
Proper maintenance schedules will result in continued excellent
performance and extended life.
Cleaning solutions, such as a commercially available descaler,
can be obtained from your local wholesaler. Make sure the
cleaning solution is applicable for stainless steel and copper or
nickel, depending on the model, and that the manufacturer's
directions are followed. A 5% solution of phosphoric acid or
oxalic acid may be considered.
Do not heat the cleaning solution when back flushing through
the heat exchanger. Flush the heat exchanger with fresh water
after cleaning.
3
ITEM A-03-342
DATED NOVEMBER 2012
SUPERCEDES MARCH 2011
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