Weld-On Adapter; Weld-On Adapter For Fmt400-Vts (Sensyflow Vt-S) Transducer - ABB FMT400-VTS Operating Instruction

4.6

Weld-on adapter

4.6.1
When installing the transducer in pipes with larger nominal width or non-round cross-section, the weld-on adapt-
er must be welded to the pipeline under consideration of the following information:
1. The weld-on adapter must have a length L after welding (see Fig. 4-2 and Fig. 4-3)
L = h - ½ × ∅ D
– The weld-on adapter must be shortened to the corresponding length before welding. After welding in
place, a few mm of the weld-on adapter can protrude into the pipe (max. 10 mm).
– Observe the pipeline wall thickness and amount of shrinkage when welding!
– The distance h from the flange top edge of the adapter to the pipe center line must be within a tolerance
of ± 2 mm.
2. Rectangularity to the pipe axis must be absolutely kept (max. tolerance: 2°).
3. The centering pin of the adapter must be aligned in flow direction to the pipe axis (at outlet run length, behind
measuring point).
4. After welding the free passage for inserting the transducer must be at least 28 mm (if required, use drill to
clear).
5. Transducer installation:
– Insert the supplied O-ring (55 mm × 3 mm) into the provided groove.
– Push the transducer into the adapter and screw together.
Weld-on adapter for FMT400-VTS (Sensyflow VT-S)
(1) Centering pin
on outlet side
Fig. 4-2
IMPORTANT
Deviations from the stated dimension and position tolerances cause additional measuring uncertainty.
16 Thermal Mass Flowmeter FMT400-VTS, FMT400-VTCS (Sensyflow VT-S/VT-CS)

Weld-on adapter for FMT400-VTS (Sensyflow VT-S) transducer

outside
(1)
∅ d
min. 28 mm
Direction of flow
Installation of the weld-adapter
with h = 263, 425 or 775 mm (transducer lengths)
Weld-on adapter
Sealing ring groove
(upon delivery
Connection flange DN 25
(1)
∅ 33,7
Z-189341
Mounting and installation
Required accuracy of mounting
Centric mounting < ± 2 mm
Twist < ± 2°
Length h
of the outer pipe
transducer
(in mm)
263
425 > 350...700
775 > 700...1400
* This maximum pipe diameter
specification is only valid when
installing the sensor centrically in
the pipe. For larger diameters or
angular ducts a non-centric
sensor position is taken into
account for calibration.
Z-189342
Min./max.
diameter
(in mm)
100...350
*
42/14-36 EN