Chilled-Water Loop Piping Guidelines - Vertiv Liebert CW Series Installer And User Manual

4.2 Chilled-water Loop Piping Guidelines

WARNING! Risk of improper piping installation, leak checking, fluid chemistry and fluid
maintenance can cause equipment damage and personal injury. Installation and service of this
equipment should be done only by qualified personnel who have been specially-trained in the
installation of air-conditioning equipment and who are wearing appropriate, OSHA-approved
PPE.
NOTICE
Risk of frozen pipes and corrosion from improper coolant mixture. Can cause water leaks resulting in
equipment and building damage.
When the cooling unit or piping may be exposed to freezing temperatures, charge the system with the proper
percentage of glycol and water for the coldest design ambient temperature. Automotive antifreeze is
unacceptable and must NOTbe used in any glycol fluid system. Use only HVAC glycol solution that meets the
requirements of recommended industry practices. Do not use galvanized pipe.
NOTICE
Risk of piping-system corrosion and freezing fluids. Can cause leaks resulting in equipment and expensive
building damage. Cooling coils, heat exchangers and piping systems are at high risk of freezing and premature
corrosion. Fluids in these systems must contain an inhibitor to prevent premature corrosion.
The system coolant fluid must be analyzed by a competent fluid-treatment specialist before start up to
establish the inhibitor level and evaluated at regularly scheduled intervals throughout the life of the system to
determine the pattern of inhibitor depletion. The fluid complexity and variations of required treatment
programs make it extremely important to obtain the advice of a competent and experienced fluid-treatment
specialist and follow a regularly scheduled coolant-fluid system-maintenance program.
Fluid chemistry varies greatly as do the required additives, called inhibitors, that reduce the corrosive effect of
the fluids on the piping systems and components.
The chemistry of the coolant fluid used must be considered, because some sources may contain corrosive
elements that reduce the effectiveness of the inhibited formulation. Sediment deposits prevent the formation of
a protective oxide layer on the inside of the coolant system components and piping. The coolant fluid must be
treated and circulating through the system continuously to prevent the buildup of deposits and/or growth of
bacteria. Proper inhibitor maintenance must be performed to prevent corrosion of the system.
Consult fluid manufacturer for testing and maintenance of inhibitors.
Commercial-grade coolant fluid is generally less corrosive to the common metals of construction than water
itself. It will, however, assume the corrosivity of the coolant fluid from which it is prepared and may become
increasingly corrosive with use if not properly inhibited.
Vertiv recommends installing a monitored fluid-detection system that is wired to activate the automatic-
closure of field-installed coolant-fluid supply and return shut-off valves to reduce the amount of coolant-fluid
leakage and consequential equipment and building damage. The shut-off valves must be sized to close-off
against the maximum coolant-fluid system pressure in case of a catastrophic fluid leak.
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Vertiv | Liebert® CW™Installer/User Guide