Flow-X─ Function Reference
4-219
Flow-X General functions - fxISO5167_LongRadiusNozzle
fxISO5167_LongRadiusNozzle
The function calculates the mass flow rate for Long Radius Nozzle pressure differential flow devices
according to the ISO-5167 standard.
Compliance
ISO-5167 - 1991 Measurement of fluid flow by means of pressure differential devices, 1st edition, 1991
ISO-5167 Amd.1 : 1998(E)
ISO-5167 - 2003 Measurement of fluid flow by means of pressure differential devices inserted in
circular cross-section conduits running full, 2nd edition, 2003
Function inputs
Remark
EU
Range
Default
Name
Optional tag name, tag description
and tag group
Differential Pressure
Differential pressure over the primary
flow device measured at the up- and
downstream pressure tappings, which
need to be in the positions as
specified in the standard
mbar
0
Pressure
Upstream pressure value of the fluid
at metering conditions
bar(a)
0
Temperature
Down- or upstream temperature of
the fluid at metering conditions
°C
0
Density
Down or upstream density of the fluid
at metering conditions
kg/m3
0
Dynamic Viscosity
Dynamic viscosity of the fluid
Pa.s
0
Isentropic Exponent
Also referred to as
(kappa). For an
ideal gas this coefficient is equal to
the ratio of the specific heat capacity
at constant pressure to the specific
heat at constant volume. According to
the ISO standard this ratio may be
used, when the real value is
unknown.
-
0
Pipe Diameter
Internal diameter of the pipe at
reference temperature
mm
0
Pipe Expansion factor
The thermal expansion coefficient of
the pipe material
1/°C
0.0000108
Pipe Reference temperature
The reference temperature that
corresponds to the 'Pipe diameter'
input value
°C
20
Long Radius Nozzle
Diameter
Long Radius Nozzle diameter at
reference temperature
mm
0
Long Radius Nozzle
Expansion factor
The thermal expansion coefficient of
the Long Radius Nozzle material
1/°C
0.0000163
Long Radius Nozzle
Reference Temperature
The reference temperature that
corresponds to the 'Long Radius
Nozzle diameter' input value
°C
20
Pressure Location
1: Upstream
Input 'Pressure' represents the
pressure at the upstream
pressure tapping (p
1
).
Since the absolute pressure is
usually measured at the
upstream tapping this is the
most common setting.
2: Downstream
Input 'Pressure' represents the
-
1
Содержание flow-x
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