Installation of Temperature Sensors:
There are a wide variety of
ways to attach temperature sensors to their site of operation: they can be screwed
in, flange-mounted, welded in, bonded etc. Choosing an appropriate
attachment mode depends on the spatial and design conditions at
the installation location and on the temperature, pressure, current and
chemical stresses prevailing there. Operating conditions determine whether
temperature sensors are inserted with or without an external
protection tube. The standard installation/attachment options are
listed below:
- Stud-end with cylindrical or conical external thread,
welded on to the protection tube or soldered on to the sheath tube
- Flange welded on to the protection tube
- Using a weld-in protection tube, which is welded in directly or into a
process-side connecting sleeve
- Collar welded on to the protection tube and corresponding cap nut with
internal thread
- Re-adjustable flange with process-side counterflange, which can be moved
on the protection tube (variable fitting length, gas-tight up to around 1 bar)
- Threaded bush which can be moved on the protection tube (variable fitting
length, gas-tight up to around 1 bar)
- Via a compression fitting with a pressure ring made of PTFE (specially
suited to sheathed thermocouple assemblies and sheathed resistance
thermometers, detachable, variable fitting length, usable up to 200 °C and 10
bar)
- Via a compression ring fitting with a wedge ring made of (stainless) steel
(specially suited to sheathed thermocouple assemblies and sheathed resistance
thermometers, wedge ring not detachable once it has been tightened, usable at
temperatures up to around 350°C and at pressures up to 40 bar)
- By means of a bayonet cap and process-side screw-in nipple (is
mostly used with temperature sensors for plastic processing machines, not
gas-tight or liquid-tight)
- Attachment to surfaces by means of screwing (e.g. using a tube clamp),
welding or bonding the temperature sensor
Note: Sheet 2 of VDE / VDI (Association of German Engineers) Guideline 3512
describes and illustrates possible installation and attachment types.
Go to "Installation and
Operating Instructions"
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