Installation Mechanical
18
RTAF-SVX001A-EN
Chilled Water Piping
Recommendations
Drainage
Locate the unit near a large capacity drain for water vessel
drain-down during shutdown or repair. Evaporators are
provided with drain connections. A vent on top of
evaporator waterbox prevents vacuum by allowing air into
evaporator for complete drainage. All local and national
codes apply.
Water Treatment
Dirt, scale, products of corrosion, and other foreign
material will adversely affect heat transfer between the
water and system components. Foreign matter in the
chilled-water system can also increase pressure drop and
consequently, reduce water flow. Proper water treatment
must be determined locally, depending on the type of
system and local water characteristics.
Evaporator Piping
Evaporator water connections are grooved.
Thoroughly flush all water piping to the unit before making
the final piping connections to the unit. Components and
layout will vary slightly, depending on the location of
connections and the water sources.
An air vent is located on top of the evaporator at the chiller
water inlet. Be sure to provide additional air vents at the
highest points in the piping to remove air from the chilled
water system. Install necessary pressure gauges to
monitor the entering and leaving chilled water pressure.
Provide shut off valves in lines to the gauges to isolate
them from the system when they are not in use. Use
rubber vibration eliminators to prevent vibration
transmission through the water lines.
If desired, install thermometers in the lines to monitor
entering and leaving water line to control water flow
balance. Install shutoff valves on both the entering and
leaving water lines so that the evaporator can be isolated
for service.
To prevent damage to chilled-water components, do not
allow evaporator pressure (maximum working pressure)
to exceed 150 psi (10.5 bar).
A pipe strainer must be installed in the entering water line.
Failure to do so can allow waterborne debris to enter the
evaporator.
Evaporator Piping Components
Piping components include all devices and controls used
to provide proper water system operation and unit
operating safety. A typical RTAF evaporator piping is
shown below.
NOTICE:
Proper Water Treatment!
The use of untreated or improperly treated water could
result in scaling, erosion, corrosion, algae or slime. It is
recommended that the services of a qualified water
treatment specialist be engaged to determine what
water treatment, if any, is required. Trane assumes no
responsibility for equipment failures which result from
untreated or improperly treated water, or saline or
brackish water.
NOTICE:
Equipment Damage!
If using any commercial flushing/cleaning solution,
construct a temporary bypass around the unit to
prevent damage to internal components of the
evaporator/condenser. Trane assumes no responsibility
for equipment damage caused by flushing/cleaning
solutions or water-born debris.
NOTICE:
Equipment Damage!
The chilled-water connections to the evaporator are to
be “grooved pipe” type connections. Do not attempt to
weld these connections, because the heat generated
from welding can cause microscopic and macroscopic
fractures on the cast iron water boxes that can lead to
premature failure of the water box. An optional grooved
pipe stub and coupling is available for welding on
flanges.
