Heating - Modulating Valve Piping - Daikin AVV Installation And Maintenance Manual

Heating – Modulating Valve Piping
Hot Water (or 2-pipe CW/HW) Modulating
Valve Piping
When piping the modulating valve, refer to the arrows on
the modulating valve body to determine the direction of
flow. The valve should be installed 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 Applied 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 arrow 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 may result.
2-Way Modulating, Normally Open, Hot
Water or 2-pipe CW/HW Valve Piping
(typical)
The 2-way Modulating hot water (or 2-pipe CW/HW)
valve is furnished normally open to the coil. When the
valve is de-energized (off) there is full flow through the
coil. Energizing the valve reduces the volume of water
flow in a modulating fashion.
Figure 88: 2-Way Modulating Valve Control, Normally
Open, Hot Water or 2-pipe CW/HW Piping
Return
Balancing and Shutoff Valve
Modulating
AB
OCT Sensor
(2-pipe CW/HW
Units Only)
Shutoff Valve
Supply
IM 817-7
2-Way
Unit Coil
Valve
A
Return
Supply
Unions
3-Way Modulating, Normally Open, Hot
Water or 2-pipe CW/HW Valve Piping
(typical)
The 3-way Modulating hot water (or 2-pipe CW/HW)
valve is furnished normally open to the coil. When the
valve is de-energized (off) there is full flow through the
coil. Energizing the valve allows a varying amount of
water to bypass the coil.
Figure 89: 3-Way Modulating Valve Control
Return
Balancing and Shutoff Valve
Modulating
AB
Balancing Valve
OCT Sensor
(2-pipe CW/HW
Units Only)
Shutoff Valve
Supply
Note: The A port is always piped to the coil. Actuator to be
configured for A port to be Normally Open.
34
3-Way
Union
Unit Coil
Valve
A
Return
B
Supply
Union
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