Siemens SITRANS FUS1020, Manual, Page: 60 / 251

3-5
1020NFM-1D Section 3
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Do not, if possible, install the transducers downstream from a throttling valve, a mixing tank, the
discharge of a positive displacement pump or any other equipment that could possibly aerate the
liquid. The best location will be as free as possible from flow disturbances, vibration, sources of
heat, noise, or radiated energy.
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Avoid mounting the transducers on a section of pipe with any external scale. Remove all scale,
rust, loose paint, etc., from the location.
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Do not mount the transducers on a surface aberration (pipe seam, etc.).
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Do not mount transducers from different ultrasonic flowmeters on the same pipe. Also, do
not run the transducer cables in common bundles with cables from communication equipment,
other Controlotron systems, or any type of ultrasonic equipment. You can run these cables through
a common conduit ONLY if they originate at the same flowmeter.
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Never mount transducers under water, unless you order submersible units and you install them in
accordance with factory instructions.
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Never mount transducers on the top or bottom of a horizontal pipe. The best placement on a
horizontal pipe is either the nine o’clock or three o’clock position for Reflect Mode, or one trans-
ducer at nine o’clock and one transducer at three o’clock for Direct Mode. Mounting on a vertical
pipe is recommended only if flow is in the upward direction.
When mounting on a vertical pipe
flowing in a downward direction make sure there is sufficient back pressure in the system to main-
tain a full pipe.
3.3.3 CLAMP-ON TRANSDUCER MOUNTING MODES
Siemens clamp-on transducers support Direct or Reflect mounting modes. The flow computer rec-
ommends a mounting mode after analyzing your pipe and liquid data entries. However, you can install
clamp-on transducers in the way that best suits your application and the transducer type you pur-
chased.
END VIEW OF PIPE
(Horizontal Plane)
Transducer located
at 9 o'clock
Transducer located
at 3 o'clock
REFLECT MOUNT
(Pipe shown in Top View for ease in visualizing sonic path)
Upstream
Transducer
Sonic Path
Pipe
Downstream
Transducer