Siemens ST-H - Standpipes

Appendix A: Applications
A.1 Liquids applications
Transducers
42 Compact Operating Instructions, 01/2018, A5E43390688_AA
A.1.3
Standpipes
Open Channel Flow Measurement
In many applications, access must be made via a standpipe. In such cases, a Siemens
flange adapter can be used to mate to the flanged standpipe. Another option is to hang the
transducer from a blind flange, respecting chemical compatibility.
The standpipe length should be as short and the diameter as large as possible. As a rule of
thumb, the -3 dB cone of the sound beam should not intersect the standpipe wall in
applications opening into a vessel or larger area. Otherwise, additional blanking will be
required to compensate for the interference zone created by the opening.
Note
When using a stilling well, make sure there is no build
-up, welds, couplings, or other debris
on the inside of the well wall. This can affect reliability of level measurement.
①
Flanged transducer
①
No vessel
②
No intersection
③
Vessel
No additional blanking required
No additional blanking required