Standpipes And Stilling Wells - Milltronics XRS-5 Instruction Manual

Standpipes and Stilling Wells

In many applications, access must be made via a standpipe. In such cases,
Milltronics can provide factory flanged transducers or split flange kit that will
readily mate to the flanged standpipe. Another option is to hang the
transducer from a blind flange.
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.
vessel
no additional blanking required
transducer
can read
level inside
or below
standpipe
no additional blanking required
Page 14
flanged
transducer
no
intersection
blind flange
mounting
vessel
standpipe
end cut on a
45° angle
typically
near blanking extension of 150 mm (6")
past end of standpipe may be required.
XRS-5 Transducer
no
vessel
no additional blanking required
vent
blind flange
mounting
transducer
sound beam
intersects
reflection at
interference
zone created
by opening
PL-590