Piping - Trane Quantum CLCPEuro Installation & Maintenance Manual

Steam Coil Piping
Type A, AA Steam Coils
These are for central system, industrial
and process application with one row,
opposite-end connections. Maximum
standard operating limits:
Copper tubes: 100 psig and 400
Type AA coils feeds alternate tubes.
Refer to Figure 13 for typical steam coil

piping.

CAUTION
!
Condensate must flow freely from
coil at all times to prevent physical
coil damage from water hammer,
unequal thermal stresses, freeze-up
and/or corrosion.
Complete the following
mendations to prevent
damage.
1. lnstall a 1/2 inch, 15 degree swing
check vacuum breaker in the
unused condensate return tapping
as close as possible to the coil.
2. Vent the vacuum breaker line to the
atmosphere or connect it to the
return main at the discharge side of
the steam trap.
Note: Vacuum breaker relief is
mandatory when the coil is controlled
by a modulating steam supply or a two-
position (ON-OFF) automatic steam
supply valve.
3. Run the return pipe at the full size of
the steam trap connection except for
the short nipple screwed directly
into the coil condensate connection.
Do not bush or reduce the coil return
tapping size.
4. Proper steam trap selection and
installation is necessary
satisfactory coil performance and
service life. For installation, use the
Assembly & Installation
following steps:
•
Select trap based on maximum
possible condensate rate.
•
Locate the steam trap discharge
at least 12 inches below the
condensate return tapping, this
provides sufficient hydrostatic
o
F
head pressure to overcome trap
losses and assure complete
condensate removal.
•
Float and thermostatic traps are
recommended because of gravity
drain and continuos discharge
operation.
•
Use float and thermostatic traps
are recommended because of
gravity drain and continuos
discharge operation.
•
Use float and thermostatic traps
recom-
with atmospheric pressure gravity
coil
condensate return, with automatic
control or where the possibility of
low-pressure supply steam exists.
•
Use bucket traps ONLY when the
supply steams in unmodulated
and 25 psig or higher.
•
Always install strainers as close
as possible to the inlet side of the
trap. Do not modulate Type A, AA
coils. Use two position (ON-OFF)
steam supply controls.
Figure 13
Typical Piping for Steam Coil
for
AV - Automatic or manual air vent
GV - Gate valve
VB - Vacuum breaker
OV - Automatic two-position control valve
5.
Caution: Always open the steam
supply control valve slowly to
prevent possible coil damage.
6.
7.
8.
9.
10.
MV - Magnetic valve
FT - Float and thermostatic steam trap
ST - Strainer
21
TRANE
Use a V-port modulating valve to
obtain gradual modulating action.
CAUTION
!
Do not modulate systems with
overhead or pressurized returns
unless the condensate is drained
by gravity to a receiver (vented to
the atmosphere) and returned to
the main by a condensate pump.
At start-up on units with fresh air
dampers, slowly turn the steam on
full at least 10 minutes before
opening the fresh air.
Pitch all supply and return steam
piping down minimum of 1-inch
per 10 feet in the direction of flow.
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.
Overhead return require 1 psig of
pressure at the steam trap
discharge for each 2 - feet
elevation to assure continuous
condensate removal.
R