www.DaikinApplied.com 37
IM 830-6
For Steam Systems:
The optional factory-supplied Daikin MicroTech Modulating
Control Valve for steam applications is the 2-way type. It
is shipped separately from the unit ventilator to help avoid
shipping damage, yet provide the installer with maximum
flexibility in making the field piping connection.
For steam applications, the 2-way, angle pattern valve
furnished is normally piped open to the coil. All steam coils are
1-1/8" (34mm) female sweat connections. Coil connections
terminate 9" (229mm) from the end of the unit.
Steam coils have a factory-installed pressure equalizing
valve and a 24" (610mm) long pressure equalizing line that
terminates in a 1/2" M.P.T. fitting.
Steam connections may be same end as cooling coil
connections, but are recommended to be opposite end to
facilitate piping. When using MicroTech controls, they must be
opposite end.
See
through
vacuum breaker tube to the downstream return line. Make this
connection downstream of the trap outlet.
Figure 66: 2-Way Steam Modulating Valve Control - Same End
Drain Connection (Coils 68/69)
Table 31: Descriptions for
1&2 Shutoff valves (Provided by Others)
3 Supply-coil connection and stub-up union
4 Return-coil connection and stub-up union
5 Flexible supply hose swivel connection
6 Two-way steam modulating control valve (Daikin)
7 Vacuum breaker tube (Daikin)
8 Float and thermostatic steam trap (by Others)
9 2-way End of Cycle valve (EOC)
Steam Coil Piping
Figure 67: Face and Bypass With 2-way End-of-Cycle
Valve - Same End Drain Connection (Piping Within Unit End
Compartment)
Table 32: Descriptions for
1&2 Shutoff valves (Provided by Others)
3 Supply-coil connection and stub-up union
4 Return-coil connection and stub-up union
5 Flexible hoses swivel connections
6 Two-way End of Cycle steam control valve (Daikin)
7 Vacuum breaker tube (Daikin)
8 Float and thermostatic steam trap (by Others)
Heating – Modulating Valve Piping
Hot Water (or 2-pipe CW/HW)
When piping the modulating valve, refer to the arrows on the
modulating valve body to determine the direction of flow. Install
the valve so that there is a 2" (51mm) minimum clearance to
remove the actuator form the valve body. Provide unions for
removal of unit coil and/or control valve as a future service
consideration. Hot water connections may be same end as
cooling coil connections, but are recommended to be opposite
end to facilitate piping. When using Daikin MicroTech controls,
they must be opposite end. The modulating valve accessory
must be field installed on the unit for which it was selected.
CAUTION
!
Refer to the arrows on the modulating valve body to determine the
direction of flow. If the valve is mounted improperly, the unit will not
operate properly and damage to the valve can result.
