14
Flat weld flanges (for 2.5 MPa pressure) are used to mount the
MFT into the pipeline:
- For DN10, DN15
– flanges of design type B (with a fixing ridge)
- For DN20-DN150
– flanges of design type F (with a notch)
Modification of flanges is needed before welding which means
drilling a threaded hole M5 on the flange cylindrical surface to fix wires
(Fig.A.2).
DN, mm D6, mm h2, mm db, mm
Workpiece
10
35 Н12 2,5±0,2
10
Flange 20-25-01-1-B St25
15
40 Н12 2,5±0,2
15
Flange 20-25-01-1-B St25
1
– revision to F;
2
– threaded hole М5
Fig.A.2. Modifications made for flanges for mounting MFT's of wafer type
When welding flanges shown in Fig.A.2 to the pipeline, adaptor
pipes shall be used (see Fig.A.3). The length of the adaptor pipes
should be no less than the length of the straight pipeline run (see
Table 1 of this manual).
After welding the flange to the adaptor pipe, process the surface
adjacent to the flowmeter as shown in Fig.A.4. The adaptors and
pipeline sections are welded butt-to-butt.
