Installation and Maintenance Manual

Installation—Mechanical
40 UNT-SVX07D-EN
5. Adjust the circuit setter valve by turning the valve stem
until the appropriate pressure drop is achieved.
6. After achieving the proper set
ting, slightly loosen the
two socket head cap screws and rotate the memory
stop around until it touches the back side of the
indicator. Then tighten the screws to securely set the
open memory position. The memory stop indicates the
last set open position.
7. If using a three-way valve: close the contr
ol valve to the
coil, with the differential pressure meter still
connected. This will divert flow to the bypass side of a
three-way valve.
Adjust the balancing fitting to o
btain the same pressure
drop across the circuit setter valve as in step two when the
control valve was open to the coil.
Note: Instructions for using this chart appear on the
preceding page. For the manual circuit setter
provided with fan-coil or Force-Flo units, use the
‘M’.
1. Make piping connections to the steam coil as shown in
Figure 14. Cap the unused connection.
2. The coil is already pitched w
ithin the unit to provide
proper pitch to drain condensate out of the coil. Verify
that the unit has been properly leveled.
3. Install a 1/2-inch, 15-degree swing check vacuum
break
er in the unused condensate return tapping as
close as possible to the coil.
4. Vent the vacuum breaker line to atmosphere or
connect it into
the return main at the discharge side of
the steam trap.
5. Pitch all steam supply and return mains down a
mi
nimum of one inch per ten feet in the direction of
flow.
6. Do not drain the steam mains
or take-off through the
coils. Drain the mains ahead of the coils through a
steam trap to the return line.
7. Overhead returns require one psig of pressur
e at the
steam trap discharge for each two-feet elevation to
ensure continuous condensate removal.
8. Proper steam trap selectio
n and installation is
necessary for satisfactory coil performance and
service life. For installation, use the following steps:
a. Position the steam trap discharge at least 12 inches
below the condensate return connection. This
provides sufficient hydrostatic head pressure to
overcome trap losses and ensure complete
condensate removal.
b. Trane recommends using flat and thermostatic
traps because of gravity drain and continuous
discharge operation.
c. Use float and thermostatic traps with atmospheric
pressure gravity condensate return, with automatic
controls or where the possibility of low pressure
supply steam exists.
d. Always install strainers as close as possible to the
trap inlet side. Reference Figure 13 for an example
of a properly piped steam coil.
Figure 12. Manual circuit setter valve, differential
pressure vs. flow
NOTICE:
Coil Damage!
In all steam coil installations, the condensate return
connections must be at the low point of the coil to
ensure condensate flows freely from the coil at all
times. Failure to do so could cause physical coil
damage from water hammer, unequal thermal stresses,
freeze-up and/or corrosion.
UNT-SVX07_-EN.book Page 40 Friday, April 27, 2012 9:40 AM