Inlet And Outlet Sections; Installation At High Ambient Temperatures; Sensor Insulation - ABB SensyMaster FMT230 Commissioning Instruction

8 SENSYMASTER FMT230, FMT250 THERMAL MASS FLOWMETER | CI/FMT230/250-EN REV. A
4.1.2

Inlet and outlet sections

The figures below show the recommended inlet and outlet
sections for various installations.
A
< 7°
≥15 x DN ≥5 x DN
C
≥ 20 x DN ≥ 5 x DN
E
≥ 40 x DN ≥ 5 x DN
Fig. 2: Inlet and outlet sections
Installation
A Pipe extension
B Pipe reduction
C 90° Pipe elbow
D 2 x 90° Pipe elbow in
one level
E 2 x 90° Pipe elbow in
two levels
F Turn-off device
To achieve the specified measuring accuracy, the indicated inlet
and outlet sections are required.
In case of combinations of several inlet-side errors, e.g. valve
and reduction, a longer inlet section must always be taken into
account.
In case of confined spaces at the installation place, the outlet
section can be reduced to 3 x DN. However, reducing the
specified inlet section will reduce the achievable level of
accuracy.
A high repeatability of the measured value is maintained.
In case of insufficient inlet and outlet sections, a special
calibration may be possible. To do this, a detailed alignment is
necessary for individual cases.
The specified inlet and outlet sections must be doubled for
gases with a very low density (hydrogen, helium).
B
< 7°
≥15 x DN
D
≥ 25 x DN
F
≥50 x DN
Inlet section Outlet section
min. 15 x DN min. 5 x DN
min. 15 x DN
min. 20 x DN
min. 25 x DN
min. 40 x DN
min. 50 x DN
4.1.3

Installation at high ambient temperatures

r
≥5 x DN
Fig. 3: Mounting position at high ambient temperatures
≥ 5 x DN
Under high but permissible ambient temperatures, avoid
additional thermal stress from heat convection or radiation,
since these sources of heat may exceed the permissible
ambient temperature on the equipment surface.
If the device needs to be installed directly on a hot, horizontal
piping, we recommend installing it on the side. In such cases,
you should avoid installing it in the 12 o'clock position,
≥5 x DN
otherwise the warm air that rises up will cause additional
G12064
heating of the electronics.
4.1.4

Sensor insulation

Fig. 4: Insulation of the sensor
1 Insulation
The sensor may be insulated as shown in Fig. 4.
a
1
G12338
G10858