30
CLCH-SVX009A-EN
Coil Piping and Connections
General Recommendations
Proper installation, piping, and trapping is necessary to
ensure satisfactory coil operation and to prevent
operational damage:
•
Support all piping independently of the coils.
•
Provide swing joints or flexible fittings on all
connections that are adjacent to heating coils to
absorb thermal expansion and contraction strains.
Note:
The contractor is responsible for supplying the
installation hardware.
•
For best results, use a short pipe nipple on the coil
headers prior to making any welded flange or welded
elbow type connections.
•
Pipe coils counterflow to airflow.
•
When attaching the piping to the coil header, make the
connection only tight enough to prevent leaks.
Maximum recommended torque is 200 foot-pounds.
•
Use pipe sealer on all thread connections.
•
After completing the piping connections, seal around
pipe from inner panel to outer panel.
Drain Pan Trapping
Condensate drain connections are provided on only one
side of the coil section. Pitch the connection lines
horizontal or downward toward an open drain. Trane
recommends installing a plug to facilitate cleaning of the
trap. See
Table 7
for drain connection sizes.
Figure 28
illustrates the proper trapping, piping, and
operation of the trap. Use the formula under the figure to
determine the correct minimum depth for the condensate
trap. If a section has a drain pan for cleaning purposes
only, it does not need a trap; however, a cap or shutoff
valve should be installed on the drain connection. Only
sections handling condensate, such as a cooling coil
section or moisture eliminator section, require a trap.
NOTICE:
Connection Leaks!
Use a backup wrench when attaching piping to coils
with copper headers to prevent damage to the coil
header. Do not use brass connectors because they
distort easily and could cause connection leaks.
NOTICE:
Over Tightening!
Do not use Teflon-based products for any field
connections because their high lubricity could allow
connections to be over-tightened, resulting in damage
to the coil header.
NOTICE:
Leakage!
Properly seal all penetrations in unit casing. Failure to
seal penetrations from inner panel to outer panel could
result in unconditioned air entering the module, and
water infiltrating the insulation, resulting in equipment
damage.
WARNING
No Step Surface!
Do not walk drain pan. Walking on the drain pan could
cause the supporting metal to collapse, resulting in the
operator/technician to fall. Failure to follow this
recommendation could result in death or serious injury.
NOTICE:
Water Damage!
When more than one section has a drain pain, trap
each section individually. Connecting all drains to a
common line with only one trap can result in
condensate retention and possible water damage to
the air handler or adjoining space.
Table 7.
Drain connections
Unit size
Connection size
3-6
0.75 inch
8-21
1.00 inch
25-30
1.25 inches
Notes:
Nominal schedule 40 on PVC drain pan.
Threaded connection size on stainless drain pan.
