Product Overview

Function
The FlowCal automatic ow balancing valve guarantees a constant ow 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 tight tolerance (approximately 10%) and offer a
wide range of operation.
*These values are for this example. The same logic applies to the other Differential Pressure Control Ranges: 2 -14, 4 - 34, and 5 -35 psid.
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.
FLUID THRUST
FLUID THRUSTFLUID THRUST
FLUID THRUSTFLUID THRUSTFLUID THRUST
FLUID THRUSTFLUID THRUSTFLUID THRUST
FLUID THRUSTFLUID THRUSTFLUID THRUST
FLUID THRUST
FLUID THRUST
FLUID THRUST
FLUID THRUSTFLUID THRUST
FLUID THRUST
2 psi 32 psiDIFFERENTIAL
PRESSURE
FLOW RATE
Nominal
Range ∆p 2–32 psi
DIFFERENTIAL
PRESSURE
FLOW RATE
Nominal
Control range
Initial p
Final
p
2 psi 32 psi
Range ∆p 2–32 psi
FLOW RATE
DIFFERENTIAL
PRESSURE
Nominal
2 psi 32 psi
FlowCal Compact Dynamic 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)*