ONICON F-4000 Series - Manual (Page 11)

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F-4000 Series Ultrasonic Flow Meter Manual 05/15 - 0707-13 / 18838 Page 11
• 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.
• Avoid mounting the transducers on a section of pipe with any external scale. Remove all
scale, rust, loose paint, etc., from the location prior to mounting the transducers.
• Do not mount the transducers on a surface aberration (pipe seam, etc.).
• Do not mount transducers from different ultrasonic flow meters on the same pipe.
• Do not run the transducer coaxial cables in common bundles with cables from other
instrumentation. You can run these cables through a common conduit ONLY if they originate
at the same flow meter.
• Never mount transducers under water, unless you have specifically purchased submersible
transducers and you install them in accordance with factory instructions.
• Avoid mounting transducers on the top of a horizontal pipe. The best placement on a
horizontal pipe is either the 10:00 or 2:00 position for reflect mode, or one sensor at 9:00 and
one sensor at 3:00 for direct mode.
• Do not mount transducers on the bottom of a horizontal pipe.
• 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 maintain a full pipe.
IMPORTANT NOTE
In some cases, longer straight runs may be necessary where the transducers are placed downstream
from devices which cause unusual flow profile disruptions or swirl; for example, modulating valves
or two elbows in close proximity and out of plane, etc.
i
The Transducers
For best results, the transducers must be installed on a straight run of pipe, free of bends, tees,
valves, transitions, insertion probes and obstructions of any kind. For most installations, ten
straight unobstructed pipe diameters upstream and five diameters downstream of the transducers
is the minimum recommended distance for proper operation. Additional considerations are
outlined below.
Flow
10 Dia. 5 Dia.