KMC Controls VCZ-44 Series - Manual (Page 2)

VEZ-41/44 Series, 2-Way/3-Way, NPT, Pneumatic Zone Control Valves 2 Installation Guide
Diverting
As the valve stem moves downward, the flow
through VCZ-44 ports AB-A decreases and the flow
through ports AB-B increases. As the valve stem
moves upward, the flow through ports AB-A in-
creases and the flow through ports AB-B decreases. If
there is a loss of signal pressure, the actuator returns
the valve to its normal position—the valve fails with
flow to port A.
Mixing
The three-way VCZ-44 zone valves are diverting
valves. However, they may be used as mixing valves
when connected in the return flow as shown in the
diagram below and if system and differential pres-
sures are within the gray area of the chart below.
+ Bypass Coil
Three-Way Valve in Return Flow
B
AB A
Pressure
(See
Chart)
COM
A
B
AB
14.5 (100)
11.6 (80)
20.3 (140)
17.4 (120)
8.7 (60)
5.8 (40)
4.3 (30)
94 (650)
2.9 (20)
14.5
(100)
29
(200)
43.5
(300)
58
(400)
72.5
(500)
87
(600)
101.5
(700)
116
(800)
130.5
(900)
System Pressure in psi (kPa)
Differential Pressure
in psi (kPa)
Allowable Mixing Applications
3-Way Valve Applications
Connection
Connect the main air supply (30 psi max.) to the 1/8"
NPT port on the top of the actuator.
1/8" NPT
Air Connection
Ring Nut to
Valve Body
1
2
Mounting Actuator on Valve Body
REMOVE Black
Plastic Attachment
Support Ring
if Present