VP531A,C
Pneumatic Terminal Unit Valves
INSTALLATION INSTRUCTIONS
BEFORE INSTALLATION
The VP531A,C Valve is a single seated, normally-open,
straight-through pneumatic valve designed to provide equal
percentage flow in terminal units. It is available with NPT
threaded or soldered end connections.
The valve should be installed so the stem is anywhere
between upright and horizontal. The actuator cannot be lower
than the body. The direction of flow must be in the same
direction as the arrow on the valve body.
Refer to Fig. 1 for dimensions to determine the amount of
space required for proper installation. Be sure to allow enough
clearance around the actuator top for servicing the valve after
installation.
A
D
C
C
2-1/4 (DIA)
(54)
AIR CONNECTION FOR
1/4 IN. (6 mm) O.D. TUBING
1-1/2
(38)
B
A
1
(25)
3-1/2
(89)
NPT THREADED BODY
SOLDER BODY
1-1/2
(38)
MINIMUM
CLEARANCE
FOR
SERVICING
VALVE
REUSABLE COPPER
RING SEAL FOR
BONNET NUT
C7987A
INSTALLATION
Actuator Spring Selection
Series 2 VP531C Valves are built with a green (2-5 psi)
actuator spring. Shipped with the valve is a loose orange
(3-10 psi) spring. If desired, you can replace the green spring
with the orange. To make this change, you must remove the
cover fastener (see Fig. 2).
Before using the orange spring, make sure it can provide
adequate close off for the application. Review the close-off
ratings in Fig. 5.
VP531A,C Soldered Body (Fig. 2)
CAUTION
Soldered Body Valve Damage Hazard.
Connecting the valve without removing the
internal assembly can overheat and damage the
plug and packing beyond repair.
Remove the top and insert assembly before
connecting the VP531 soldered body valve.
The valve is shipped with a loose bonnet nut allowing easy
removal of the top and insert assembly. Lift the assembly out
before soldering the valve into place.
When soldering is completed, replace the top and insert
assembly and tighten the bonnet nut firmly enough to
compress the copper washer seal (35 to 45 ft-lb torque).
Body Size
A
B
C
D
1/2 in. NPT
(1.6 or 2.3 Cv)
1/2 in. pipe
4-1/8 in.
(104 mm)
2-9/32 in.
(58 mm)
–
3/4 in. NPT
(2.6 or 3.3 Cv)
3/4 in. pipe
4-3/16 in.
(106 mm)
2-7/16 in.
(61 mm)
–
1/2 in. Solder
(1.6 Cv)
5/8 in. (16 mm) O.D.
copper tubing
4-1/8 in.
(104 mm)
1-5/8 in.
(41 mm)
1/2 in.
(13 mm)
3/4 in. Solder
(2.6 or 3.3 Cv)
7/8 in. (22 mm) O.D.
copper tubing
4-3/16 in.
(106 mm)
1-1/2 in.
(38 mm)
3/4 in.
(19 mm)
Fig. 1. Approximate dimensions of
VP531A,C in in. (mm).
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