CR4 - The Engineer's Place for News and Discussion ®


Previous in Forum: Smoke Detectors   Next in Forum: Calorimetry Under flow
Close
Close
Close
4 comments
Participant

Join Date: Jun 2016
Posts: 4

Flow Transmitter Problem Water Carryover in Process Line, Orifice Type, Direct

07/21/2016 5:58 AM

Orifice type Direct flow tranmsitter(0-2500mmwc) desgined for KERO(sp.gravity 0.845) of process line SKO to SRGO malfunctions due to water carryover with KERO. After draining the water means flushing the impulse lines flow transmitter shows proper reading for about 5/6 hours. Due to water carryover with KERO, differential pressure gets dropped i.e slowly goes to negative, hence flow transmitter readings drops and goes to Zero. Tried with filling glycerine in the impulse lines and Water in impulse lines also. Same result, worked for few hours. again readings goes to Zero. what will be the solution in this case. kindly let me know. asper plant operation water carryover with KERO is normal thing from operation point of view and it may happen also. So How to make the flow tranmsitter works.Any solution?? kindly let me knwo

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
Australia - Member - New Member

Join Date: Feb 2008
Location: Australia
Posts: 1712
Good Answers: 200
#1

Re: Flow Transmitter Problem Water Carryover in Process Line, Orifice Type, Direct

07/21/2016 7:46 AM

Not my specialty, so please regard the following as a guess rather than expert opinion.

For the differential signal to go "negative" would imply that the sensor is below the line level and that one of the impulse tubes is filling with a more dense material (That you believe to be water.).

Maybe have the lines connected from above mid-line of pipe, and sensor at same level.

I also believe that I saw a differential monitor that had some continuous "bleed-through" so that any contaminant would not accumulate in the sensor tubes.

good luck in your quest for an answer.

__________________
Just an Engineer from the land down under.
Register to Reply
Guru

Join Date: Jul 2010
Posts: 644
Good Answers: 169
#2

Re: Flow Transmitter Problem Water Carryover in Process Line, Orifice Type, Direct

07/21/2016 9:07 AM

Do I understand properly that the flow stream is 2 phase, a component called KERO (is this kerosene, a hydrocarbon fuel?) and water. Is it primarily Kero, with little bit of water? Correct?

Have you captured the contents of the impulse tubing when draining so you can analyze the contents?

Is the high side impulse line content primarily water or kero ?

Is the low side impulse line content primarily water or kero ?

How different is the drained impulse line content from high side to low side in terms of density/SG?

What is the general operating flow rate? 50% max? 10% max? 90% max?

What is the elevation distance from the pipe/line to the transmitter ports? 50mm? 500mm? 2000mm?

What kind of OP taps are used? Flange union? D-D/2 taps? corner taps?

Where around the circumference of the pipe are the taps located? 1 and 11 o'clock? 3 and 9 o'clock? 5 and 7 o'clock?

Register to Reply
Commentator
Venezuela - Member - New Member

Join Date: Aug 2010
Location: Venezuela
Posts: 88
Good Answers: 4
#3

Re: Flow Transmitter Problem Water Carryover in Process Line, Orifice Type, Direct

07/21/2016 11:09 AM

Friend,

What is the process temperature?

Can you take a couple of photos with the orifice plate and transmitter? I mean a good photo where we can observed the process taps and transmitter, even the heights

What do you mean with Direct???

Regards

JP

__________________
Instruments-guy-SAV
Register to Reply
Power-User
Engineering Fields - Instrumentation Engineering - New Member Engineering Fields - Control Engineering - New Member Technical Fields - Technical Writing - New Member Technical Fields - Education - New Member Fans of Old Computers - Apple II -

Join Date: Sep 2011
Location: Bellingham, WA
Posts: 204
Good Answers: 47
#4

Re: Flow Transmitter Problem Water Carryover in Process Line, Orifice Type, Direct

07/27/2016 3:11 PM

Is it practical to close-couple the transmitter to the orifice flange? I have spent many an hour re-filling impulse lines with dense fluid to maintain a "water-free" state in petroleum flowmeter applications. Usually this was where the pipe was located high above in a rack, and the transmitter was located at ground level. The fill fluid must obviously be denser than water, and ideally immiscible with water. After I left that job, I was told the instrument crew switched from glycerine to a Krytox (a DuPont product) for this very reason.

If it is practical to mount the transmitter closer to the pipe so you don't have vertical runs of impulse tubing to capture water, it avoids a lot of problems.

__________________
They call me "lightning" when wielding a hammer, because I never strike twice in the same place
Register to Reply
Register to Reply 4 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

Instruments-guy-SAV (1); Iris (1); Just an Engineer (1); tonykuphaldt (1)

Previous in Forum: Smoke Detectors   Next in Forum: Calorimetry Under flow

Advertisement