Wide Range of Materials
Choice of Process Connections
Pipe or Tube
Non Destructive Testing
Fabricated Pockets from Jagjan are precision components manufactured to the highest standard from pipe, tube and bar, to serve as protective devices for primary sensing elements of all types. A wide range of possible products are available. Conditions of pressure, temperature, velocity and corrosion resistance govern the size, shape and selection of materials to ensure optimum dependability, response time and accuracy.
Jagjan is experienced in the manufacture of fabricated pockets in a wide range of materials, including 304,310, 316 and 321 Stainless Steels, 446 Cr-Fe, 6% Mo, Carbon Steels, Chromium Steels, Hastelloy B3, C22, C276 and X, Incoloy 800, 825, Inconel 600 and 625, Monel 400 and Titanium.
For recommendations on the use of these materials, please refer to Technical Data Sheet JAG/TWM.
Pocket Size :-
Jagjan can fabricate pockets from a wide variety of tube or pipe sizes including 10 mm x 8 mm, ¼" NB, ½" NB, ¾" NB, 1" NB and larger, in a variety of schedules subject to requirements and process conditions.
Instrument Connection :-
Instrument connections may be male or female, in API, NPT, BSP or other thread forms.
Process Connection :-
Connection to the pipe or vessel may be by means of thread, flange or weld.
Using standard tapered or parallel pipe threads for simplicity and low cost is popular, generally for low pressure applications.
Standard threads are NPT, BSP(Pl), BSP(Tr) and API. The thread size is dependent on the application. Standard sizes range from ½" to 2".
All sizes and pressure ratings are available to DIN, BS, ANSI/ASME and JIS or other standards. Flanged connections are now the petrochemical standard for all applications.
Weld in pockets are normally used where process pressure and velocities are too great for flanged and threaded, or where long term inexpensive connections are required.
Reduced Tip :-
For applications where a quick response to changes in temperature is required, fabricated pockets may be fitted with a reduced tip. The tip is machined from bar-stock, with a bore suited to the primary element, minimising the amount of free air space around the sensor.
Immersion Length :-
The immersion length should be calculated to ensure that the sensing element has sufficient immersion into the process medium to give accurate measurement. To ensure optimum results and freedom from outside influences, the rmowell tip should be located at a point which equates with the lower portion of the centre third of the pipe line.
For tanks, the depth of immersion obviously varies considerably but, as a rule of thumb, 300 mmfrom outer wall will give ideal results.
In high velocity applications, wake frequency effects must also be considered.
Immersion length is defined as shown.
Surface Finish :-
Thermowells are supplied as standard with a fine machined surface finish. Other finishes may be supplied on request.
Special Coatings :-
Jagjan has facilities for coating thermowells to increase corrosion and abrasion resistance. Options include Stellite , Tungsten Carbide, Tantalum, Zirconium and PTFE.
Stub Flange Arrangement :-
When a fabricated pocket is manufactured from special materials, for example Inconel , Monel , Hastelloy or Titanium, it is not necessary for the whole flange to be of the same material. For economic reasons, we offer a stub flange typically 3mm thick with a diameter equal to the raised face. This is welded to the Thermowell stem and is supplied fitted with a loose backing flange normally manufactured in 316 stainless steel or carbon steel.
Weld Procedures :-
Jagjan employs well experienced welders for stainless steels, Carbon Steels and Special materials.
Quality Control / Inspection :-
Jagjan thermowells are manufactured under a strict quality control system. A wide range of documentation and Non Destructive Testing can be provided on request, including:
Certificate of Conformity
Hydrostatic Pressure Test
Positive Material Identification
Third party inspection may be arranged, and material certification to IBR can be provided.
The following are the most common fabricated pockets available from TJagjan . Other designs are available to customers’ standards, as the application requires. It is not to be implied that all pockets shown below are available in all sizes, ratings and materials. Please refer to the sales department with specific enquiries.