Function block parameters

Function

0	The function block is deactivated.
1	The calculation is performed.

Function block inputs

[a] Flow Coefficient

Fixed value.

The flow coefficients are used to consider all losses which occur when a fluid flows through an orifice plate. The flow coefficient is usually within a range between 0.7 and 0.9.

[A] Flow area orifice plate [cm²]

Fixed value

Example of circular orifice plate opening: A[cm²] = π x (r[mm])² / 100

[ρ] Density of the fluid [kg/m³]

Fixed value

Water has a density of 997.

[dP] Difference pressure [pa]

Analog channel

"Pressure downstream of the orifice plate (p1)" minus "Pressure upstream of the orifice plate (p2)"

Function block outputs

[Q] Volume flow [m³/h]

Q = 3600 x a x (A/10000) x √( 2/ρ x dP )