why the steam drum and deaerator level transmitter range is
in negative MMWC to zero
Answers were Sorted based on User's Feedback
Range is Negative mmWC to Zero because we are using "Wet leg configuration" arrangement. In which LP side of transmitter is contains a Condesate Pot always filled-in with water.
Wet leg configuration is used when the tanks contain CONDENSABLE VAPOURS, these vapours when entered impulse lines may be condensed over time and get accumulated. This accumulated liquids in impulse line creates Pressure head resulting error in level measurement. to avoid this suituation we initially fill LP side impulse line with water ( or a condensate pot is used to condense vapour and fill impulse line automatically).
| Is This Answer Correct ? | 7 Yes | 2 No |
Answer / mithilesh kumar
actually wht happen there..
level is totally depend upon vessel/drum/tank type..
means that it is open or close..
if it's open then range is in positve..
but if it's fully closed then range is start with negative..
by using level formula..
u can mail me if this formula or step is required..
email id: mithilesh.barnwal30@gmail.com
| Is This Answer Correct ? | 5 Yes | 18 No |
In both cases you are using a wet leg configuration with the
DPT. In the steam drum if you use the old fashion way by
changing the HP and LP legs around you will get a positive
mmH2O reading. If you use a piped SMART Tx or a SMART
capillary type DPT, you will get this negative mmH2O readings.
I have already done a writeup on this so go and look at
previous questions.
In the deaerator there is a vacuum but again the same wet
leg is done. I have already done a writeup on this vacuum
applications as well so go and look at previous questions.
Good luck
| Is This Answer Correct ? | 7 Yes | 30 No |
Can anyone send most commonley asked Instrumentation questions and answers in cement industry please?
i am going to attend ongc exam this coming june for Graduate Engineer Trainee post if anybody knows the question pattern or have experience plz share it with me
What is the use of valve positioner?
WHEN DO WE GO FOR FMCW TYPE RADAR & PW TYPE RADAR ?
How we can re-range the DP transmitter, range is -0.5 to 2.0bara. new range is -0.5 to 5 bar
what does 5/2 solinoid valve means?
which type of filter gives the constant phase characteristics?
How to calibrate displacer type level transmitter (chemtrol make )for level measurement in hotwell , LP & HP heater ?
Explain the working of rota meter.
what is the full form of psig.
how we can calibrate an Interface level transmitter online
There is a problem with our HART475 it is not communicating with smart devices error becomes "NO DEVICE FOUND"we have insert 250ohm resistance as per requirement but invain plz tell me the solution?
Civil Engineering (5086)
Mechanical Engineering (4456)
Electrical Engineering (16639)
Electronics Communications (3918)
Chemical Engineering (1095)
Aeronautical Engineering (239)
Bio Engineering (96)
Metallurgy (361)
Industrial Engineering (259)
Instrumentation (3014)
Automobile Engineering (332)
Mechatronics Engineering (97)
Marine Engineering (124)
Power Plant Engineering (172)
Textile Engineering (575)
Production Engineering (25)
Satellite Systems Engineering (106)
Engineering AllOther (1379)