Coil Piping and Connections
58
UNT-SVX07J-EN
Valve and Actuator Operation
•
Two position actuators are different for normally open
(N.O) and normally closed (N.C) and are capacitor
discharge return.
•
Valve operation is the same.
•
All actuators are clockwise to close and
counterclockwise to open with wire harness facing you
and looking at the top of the actuator.
Valve Stroke Time
Field-Set Flow Capacity Adjustment
•
If a different Cv is required, align the clip to the notch
scale found on the underside of the actuator to the
corresponding Cv in the table below.
•
For 3-point floating, control signals adjust the
controller stroke time parameter to match the stroke
time of the final clip position.
•
For all 3-way valves, the stroke time is 75 seconds and
there is no end stop on the actuator.
•
The Cv can not be changed for 3-way valves.
Table 22. Valve stroke time
Valve Selection
End Stop
Position
Stroke Time
(Seconds)
1/2 in. 2-way 1.4 Cv
No end stop
75
1/2 in. 2-way 2.4 Cv
5
55
3/4 in. 2-way 3.4 Cv
6
62
1/2 in. 3-way 1.0 Cv
No end stop
75
1/2 in. 3-way 2.7 Cv
No end stop
75
3/4 in. 3-way 4.6 Cv
No end stop
75
Table 22. Valve stroke time (continued)
Valve Selection
End Stop
Position
Stroke Time
(Seconds)
Table 23. Actuator clip setting
2-way Valve Body
1
2
3-
3+
4
4+
5
5+
6
N
No End Stop
1/2 in. Z2050QS-F Cv
0.1
0.2
0.4
0.6
0.8
1.2
1.4
1/2 in. Z2050QS-J Cv
0.5
0.7
1.2
1.7
2.4
(a)
3.4
4.8
5.9
3/4 in. Z2075QS-K Cv
0.5
1
1.5
2.3
3.3
4.6
6.6
9.8
Stroke time (seconds)
30
37
41
43
49
51
55
58
62
68
75
(a) This Cv shows the standard Cv offering for 2-way valves.
Figure 36.
Cv adjustments
Notice
Coil Damage!
Failure to do so could cause physical coil damage from
water hammer, unequal thermal stresses, freeze-up
and/or corrosion. In all steam coil installations, the
condensate return connections must be at the low
point of the coil to ensure condensate flows freely from
the coil at all times.
Содержание UniTrane
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