Intek 100FS - Manual (Page 7)

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Some TU transducers have an integrally mounted cable; do not pull on this cable, or attempt
to remove the fitting where the cable enters the shell.
Fluid temperatures other than ambient require special attention. Thermal gradients from one
end of the transducer to the other, as well as along the radius of the connection pipe, are
undesirable. Therefore, effective insulation should be installed around the inlet and outlet
straight line runs. Gradients which may exist in the line further up stream can be removed if
an insulated elbow is installed in the line prior to entering the straight line portion of the
plumbing. Metallic support braces for the sensor or adjoining plumbing can act as a heat sink
and cause operational problems in high temperature applications. The support braces should
be thermally isolated from the line to avoid large heat conduction effects.
If the transducer is for use above 300°F, it will have a side arm and connector box, where the
internal high temperature wiring is connected to the lower temperature transducer cable. Free
air should be allowed to flow around the side arm and connector box to keep the box cool.
The side arm can be insulated up to one third of its length from the transducer body.
The ideal installation will provide the sensor with well established smooth flow, uniform
system temperature and consistent fluid media.
2. Intrusive Probes
Straight run is not critical, but if trying to hold a precise set point, some straight run is
useful, such as 10 to 20 pipe diameters on the inlet and at least 6 diameters on the outlet.
The various probe transducers are mounted through a threaded collar (NPT/2I and NPT/I) or
flanged tee (BF/2I or BF/I). Other fittings and sensor designs are also available and are
discussed on the Custom Information page. Generally the probes are sized so the tips extend
½ to 1 inch beyond the pipe center line when properly installed. However, for larger pipes,
the probes may extend in
c of a diameter from the wall.
Proper alignment of the sensor with flow is important; the flow direction is indicated on the
transducer tag and/or etched into the transducer. All dual probe transducers (NPT/2I, BF/2I)
are installed so that the two probes are side-by-side across the fluid stream. Never rotate the
junction box that houses the terminal cable connection. If this occurs the transducer could be
damaged and/or installed misaligned with the flow direction.
For high temperature applications, the sensor and surrounding line should be well insulated.
Leave a portion of the transducer neck un-insulated to allow heat dissipation before reaching
the junction box.
2.2 ELECTRONICS
Two types of electronics housings are typically available for flow switches. These are NEMA 4 (or 4X)
and explosion-proof. These come in different sizes to accommodate options and special features.