Honeywell VRN Notice D'installation

VRN Dynamic Pressure-Regulat-
ing Control Valves and Actuators
APPLICATION
The VRN2 two-way dynamic pressure-regulating control
valves maintain constant flow of hot or chilled water with
glycol solutions up to 50% in closed-loop heating,
ventilating, and air conditioning systems, within the
specified pressure drop ranges of each model number.
These valve assemblies can be ordered with or without
factory-mounted actuators.
Application Notes
Valve sizing is important for correct system operation.
Undersized valves do not have sufficient capacity at
maximum load. Oversized valves do not have sufficient
authority over the load in modulating applications.
INSTALLATION INSTRUCTIONS
Oversized valves can cause excessive cycling and the seat
and ball can be damaged because of the restricted
opening.
Proper Use
VRN valves are intended for use in chilled water and hot
water closed loop applications only, with a temperature
range of 35 to 250°F, and pressures up to 360psig.
Water should be properly filtered, treated and conditioned
for good operating performance, and according to
recommendations of the boiler or chiller manufacturers.
The installation of strainers and filters is recommended.
Do not use with manual balancing valves.
IMPORTANT
The presence of excessive iron oxide (red rust) in
the system voids the valve warranty.
Effective Flow Rate
The built-in differential pressure regulator makes fluid
flow through the valve independent of changes in supply.
The pressure regulator virtually eliminates cavitation in
the valve, and decouples the control valve from the effects
of piping components such as reducers and elbows.
Pressure independent control valves are sized to match
design coil flow regardless of coil connection size. VRN2
valves eliminate the need to balance the system for proper
flow, and allow chillers to be operated at design
temperature differential for maximum efficiency at every
load condition. When used in a system with variable speed
pump drives, 3-way valves and coil bypass lines are not
required.
Required Operating Torque
Both Honeywell fail in place and fail-safe low torque direct
coupled actuators can be used with the VRN valves.
VRN valves use a patented seat design that reduces the
torque needed from the actuator.
Actuators with 27 lb-in torque, (for valves up to 1-1/4 in
size), and 35 lb-in torque (for 1-1/2 in size and above)
provide sufficient torque to operate the valve at rated
close-off. (See Table 1).
Maximum safe operating torque is 44 lb-in.
38-00005EFS-04