- Wide Range of Materials
- Stainless Steels
- Exotic Materials
- Choice of Process Connections
- Flanged
- Screwed
- Weld-In
- Pipe or Tube
- ASME IX Coded Welding
- Special Coatings
- Non Destructive Testing
General Description
Fabricated Pockets 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.
Specification
Materials
We are 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, Haynes Alloys
214, 230, 556 and HR-160, Carbon Steels, Chromium
Steels, Duplex and Super Duplex Stainless 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 click here
Pocket Size
We can fabricate pockets from a wide variety of tube or
pipe sizes including 11 mm x 7 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.
Threaded
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”.
Flanged
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
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,
thermowell 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 mm from outer wall will
give ideal results. In high velocity applications, wake frequency effects must
also be considered. |
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