Steam Coil Piping - Trane UCCA Installation, Operation And Maintenance Manual

Figure 28. Drain pan trapping for negative and positive pressure applications
Drain pan trapping for section
under negative pressure
L = H + J + pipe diameter where:
H = 1 inch for each inch of negative
pressure plus 1 inch
J = 1/2 H

Steam Coil Piping

Air handlers fitted with steam coils have labeled holes for
piping penetrations. Figure 29
coil piping configuration. See
system components in these figures.
The coil condensate return line must be piped full size of
the condensate trap connection, except for a short nipple
screwed directly into the coil header's condensate return
tapping. Do not bush or reduce the coil return trapping
size.
Table 8. Code of system components for piping figures
Code System component
FT Float and thermostatic steam trap
GV Gate valve
OV Automatic two-position (ON-OFF) control valve
VB Vacuum breaker
ST Strainer
AV Automatic or manual air vent
MV Modulating control valve
CLCH-SVX009A-EN
L
Drain pan trapping for section
under positive pressure
L = H + J + pipe diameter where:
H = 1/2 inch (minimum)
J = 1/2 inch plus the unit positive static
pressure at coil discharge
(loaded filters)
illustrates a typical steam
Table 8 for the codes of
Coil Piping and Connections
H
J
Figure 29. Typical piping for Type NS steam coils and
horizontal tubes for horizontal airflow
12 in. min.
ST
FT
FT
ST
Full size of
steam trap
connection
MV
GV
ST
VB
GV
Full size of
coil connection
VB
GV
Full
size ST
of
main
FT
12 in. min.
31