sviswan@technip.com wrote:
> Pressure tappings are not placed inclined, however thermowells with
> laterolet fittings are placed inclined to the length of the pipe. By
> placing at an incline, it has the advantage of accommodating the length of
> the thermowell in a smaller ID of the pipe than it would be, if placed
> otherwise. The thermowell is unlikely to create any turbulence in the flow.
> However the flow might induce a vibration on to the thermowell with a
> resultant fatigue failure of the thermowell. Thermowells are therefore
> installed with the inclination placed against the flow, which would give
> the minimum of the possible flow induced vibration on the thermowell.
Interesting answer.
The original question was:
<<Could you please tell what actually is a thermowell and why pressure tapping in horizontal pipe are provided at an angle,is to mininmize turbulence,how?>>
We had a great exchange about that subject fairly recently.
From Steve McKenzie, 30 August 2007:
<<For gases, top orientation is best as it prevents solids and any condensate entering the impulse lines, causing inaccuracy. For liquid bottom orientation helps keep the impulse lines full of liquid; gas bubbles cause inaccuracy. By shifting the tappings to say 45 degrees from bottom reduced the likelihood of entrained solids (moving along the bottom of the pipe) causing impulse tube blockage. For saturated steam, arrangement is often made to keep the impulse tubes full of condensate, so bottom or side tapping is best. For superheated steam. any condensate would tend to dry out the impulse tubes, so top tapping helps keep the impulse tubes dry.>>
Paul Received on Thu Nov 08 00:41:00 2007
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