Thermowells are not usually necessary with Burling Controls. Their heat sensing tubes are rigid and need no protection unless there is excessive pressure or a
high flow rate. They are usually made of stainless steel to resist normal conditions. Where conditions are severe or in continuous process installations,
a thermowell may be required.
table for each instrument model shows which
standard thermowell should be
used for each code number. These are shown below. It is essential that the full immersion length, "U", be exposed to the heat.
If a special well is required, order
by type, material, immersion length, "U", and lagging extension, "T", if needed. Not available for type 518B.
In all cases, the bushing or union should be located on
instrument tube so "C" or "D" equals well dimension, "U", plus lagging exten
sion, "T" (if any), plus either 3/4" (well type A-807) or 1" (well types
A-709, 518-B and A-698-1).
Well type A-666-3 is for use on
certain code numbers for Models
B-1C, B-2C, B-1X and B-2X only.
No bushing or union is used.
Well type A-970-3 can be used for high temperature service on heavy duty models with .84" OD inconel tubes. A
mounting set, part 1236, must be used.