Honeywell VP531A Fiche Technique

GENERAL
Description
The VP531A,C Pneumatic Terminal Unit Valves are single-
seated, normally open valves with a straight through body
pattern and an integral pneumatic operator. Valves are
available with either threaded NPT or soldered piping
connections. The VP531A rating is 180F (82C) maximum and
the VP531C is rated at 240F (116C) maximum.
Application
The VP531A,C, used with a direct acting room or unit
thermostat, provide proportional control of hot water in fan coil
units, finned-tube radiation, or small reheat coils. The VP531C
is used for steam systems. The valves can also be used on
chilled water coils when controlled by a reverse-acting
thermostat. Models are available with spring ranges for
sequence operation.
Operation
An increase in control air pressure causes the valve to move
toward the closed position, modulating the flow of the steam
or water supply (Fig. 1). The valve is fully open when the
control air pressure is at or under the low end of the operating
range and is fully closed when the control air pressure is at the
high end.
CONTROL AIR
STEAM OR
WATER SUPPLY
Fig. 1. Typical Valve Operation.
® U.S. Registered Trademark
Copyright © 2003 Honeywell International Inc.
All Rights Reserved
Pneumatic Terminal Unit Valve
N.O.
C4674
Specifications
Construction:
Body: Cast bronze
Disc and plug:
VP531A: Rubber.
VP531C: Brass disc holder and teflon disc.
Seat: Bronze; integral with body.
Stem: Stainless steel, 3/16 in. (5 mm) diameter.
Bonnet nut seal: Reusable copper ring.
Packing:
VP531A: Rubber, spring loaded, self adjusting.
VP531C: Teflon, spring loaded, self adjusting.
Flow Characteristics: Modified equal percentage.
Body Pressure Rating (maximum): 150 psi (1034 kPa).
Controlled Medium Temperature (maximum):
VP531A: 180°F (82°C).
VP531C: 240°F (116°C).
Maximum Difference (for alternating hot and cold water):
140°F (78K).
Maximum Pressure Differential
(for quiet service and normal disc/seat life):
Water: 20 psi (138 kPa).
Steam (VP531C only): 10 psi (69 kPa).
Actuator: Rolling diaphragm type.
Air Connection:
Integral, for 1/4 in. (6 mm) O.D. plastic tubing.
Maximum Safe Air Pressure: 30 psi (207 kPa).
Maximum Safe Diaphragm Temperature: 230°F (110°C).
Accessories:
14001101-001 Position Indicator.
14003648-001 Vandalism Resistant Assembly
(cover assembly with 1/8 in. NPT air connection and
push-in retainer to replace standard cover).
VP531A,C
SERVICE DATA
75-7251EF