Product Overview

Function
The FlowCal automatic flow balancing valve guarantees a constant flow rate when the upstream/downstream pressure differential varies.
It is therefore necessary to refer to the Dp vs. flow rate diagram and to a basic diagram illustrating the operation methods and the relevant variable
effects.
Operating principle
The FlowCal flow cartridge is composed of a cylinder, a spring-loaded piston, and a combination of fixed and variable geometric orifices through which
the fluid flows. These variable orifice sizes increase or decrease by the piston movement, contingent on the system’s fluid thrust. A specially calibrated
spring counteracts this movement to regulate the amount of fluid which may pass through the valve orifices, maintaining a balanced system. FlowCal
valves are high performance automatic flow balancing valves which control selected flow rates within a very tight tolerance (approximately 10%) and
offer a wide range of operation.
In this case, the spring-loaded regulating
piston remains in equilibrium without
compressing the spring and gives the
fluid the maximum free flow area. When
below the differential pressure control
range the piston acts as a fixed orifice
and thus the flow rate through the
FlowCal depends only on the differential
pressure.
If the differential pressure is within the
control range, the spring-loaded piston is
positioned to give the fluid a free flow area
permiting regular flow at the nominal rate
for which the FlowCal is set up.
In this case, the spring-loaded piston fully
compresses a spring and leaves only the
fixed orifice for the fluid to pass through.
The flow rate through the FlowCal depends
only on the differential pressure.
2 psi 32 psiDIFFERENTIAL
PRESSURE
FLOW RATE
G
0
Range Dp 2–32 psi where G
0
= nominal flow rate
DIFFERENTIAL
PRESSURE
FLOW RATE
G
0
Control range
Initial Dp
Final Dp
2 psi 32 psi
Range Dp 2–32 psi where G
0
= nominal flow rate
FLOW RATE
DIFFERENTIAL
PRESSURE
G
0
2 psi 32 psi
FlowCal
TM
Automatic Flow Balancing Valves
Below the differential pressure control range (< 2 psid)*
Within the differential pressure control range (2 - 32 psid)*
Above the differential pressure control range (> 32 psid)*