JOHNSON CONTROLS
78
FORM 102.20-N1
ISSUE DATE: 7/06/2016
SECTION 3 - HANDLING, STORAGE, AND INSTALLATION
•
Use the actual operating conditions (coil pressure
vs. return pressure) to select a trap.
•
It is preferable to provide an individual trap for
each coil, but a single trap may be used for coils
operating in parallel with respect to the airflow.
Coils in series with respect to airflow must be sup
-
plied with individual traps.
•
Locate the trap at least 12 in. below the coil return
connection, and lower it when freeze protection is
required. Do not attempt to lift condensate modu-
lated steam supply.
FIGURE 121 -
STEAM COIL PIPING ARRANGEMENTS
LD04887a
SUPPL
Y MAIN
DRIP TRAP
FOR END OR
LOW POINT
OF SUPPLY
MAIN
RETURN
MAIN
SUPPL
Y MAIN
SUPPL
Y
MAIN
SUPPL
Y MAIN
VENT TO
ATMOSPHERE
CLOSE TO
UNIT (NOT ON
VACUUM
SYSTEMS)
AIR FLOW
AIR FLOW
RETURN MAIN
RETURN MAIN
PITCHED IN CASING
STEAM COIL
STEAM COIL
PITCHED IN CASING
12" MIN.
12" MIN.
SINGLE COIL
VERTICAL AIR FLOW
12" MIN.
12" MIN.
12" MIN.
COILS IN PARALLEL AIR
FLOW MAY HAVE COMMON
SUPPLY AND SINGLE TRAP
(INDIVIDUAL COIL TRAP
PREFERRED)
COILS IN SERIES AIR FLOW
MUST HAVE INDIVIDUAL
TRAPS AND CONTROL
VALVES
RETURN MAIN
DIRT POCKET (FULL
SIZE OF COIL CONN.)
F & T TRAP
VACCUM
BREAKER
1/2" CHECK
VALVE
(OPTIONAL)
DIRT
(FULL SIZE
OF COIL
CONN.)
VACUUM
BRAKER
1/2" CHECK
VALVE
(OPTIONAL)
SYMBOLS FOR "SS" STEAM
COIL PIPING ARRANGEMENTS
GATE VALVE
STRAINER
CONTROL VALVE
(MODULATING OR
TWO POSITION)
CHECK VALVE
FLOAT AND
THERMOSTATIC
TRAP
