When
Thermocouples or RTD's or any other sensors are exposed
to harsh atmospheres they are damaged. This damaged
due to mechanical or chemical contamination can be
avoided by the use of protection tubes or Thermowells.
Thermowells and Protection Tubes are closed at one
end, normally the harsh environment or process end,
and opened at the termination end, various methods
are used to assemble the tube, sensor, and connection
head with termination into the process. Depending
on the chemical or mechanical environment to which
the Sensor will be subjected the material for the
protection tube is selected.
Thermowells and Protection Tubes are normally used
with RTD's, Thermocouples, or Bimetal thermometers
where temperatures are to be measured in high pressure
(over 150 PSI) or environments that are chemically
and mechanically hostile. These Thermowells and Protection
Tubes are machined from solid bar stock with high
precision and accuracy and have material tractability.
To design an efficient and safe thermowell pressure,
maximum temperature and velocity of the system need
to be known. The various designs available are shown
above however straight wells are used for low pressures
and temperatures, Stepped Thermowells and Protection
Tubes are used for a quick response time and medium
strength. 'Tapered Thermowells and Protection Tubes
are the most efficient and highly recommended design
as they have high pressure ratings, quick thermal
response and provide greater strength. These Thermowells
and Protection Tubes are more resistant to vibration
than straight wells and also work well in high velocity
applications as the taper allows fluids to flow without
restrictions.
To size Thermowells
and Protection Tubes please indicate the following:
Overall length, Process connection, Instrument or
Sensor Connection, Type of Material, Maximum Temperature,
Maximum Velocity/Pressure.
Thermowells
and Protection Tubes Features:
•
Manufactured
in various materials
• Available with tractability and registration
• Tapered, straight, stepped, and flanged
styles
•
Protection tubes available for various
metals
•
Thermowells and tubes available with fittings
• An assortment of threads and mounting
• Custom designs available