level transmitter

Dear sir,

Rosemount model (3051CD3A22A1AM5B4C6Q8) pressure transmitter used for measuring  level of heat exchanger (shell and tube)(wet leg type) with serial (1677827) but the problem that after increasing the capacity, there is sludge built up and transmitter need to drain daily. I want to solve this problem by replacing this transmitter by one of this option(from my point of view):

1- Radar type.

2-Remote seal diaphragm.

i want to guide me for the right choice.

1-if the remote seal is the right choice,

the installed flanged is 2" CL300 RF and i have already a new transmitter but the flange is small(approx. 1") so can i use increaser for this case.

2- if the radar is the right choice,

what recommended type that i use,non contact or guided.

regards,

  • Dear Ali,
    A guided wave radar is generally a good fit for heat exchangers. By using a single lead probe, potential issues with build-up can be eliminated. The Rosemount 5300 series provide several clever solutions when it comes to remote diagnostics and predicitve maintenance - and is also extremely sensitive, making the single lead probe suitable for virtually most applications. In order to give you further guidance regarding guided wave radars, we would need some further description about the application, such as measuring range and installation criterias.
    Kind regards,
    Ingemar Serneby, Sr. Application Specialist
  • In reply to Ingemar Serneby:

    the heat exchanger is already operated so i don't have bridle to put the radar transmitter.and you don't mention the reason for why we don't use remote seal as i know it is very suitable for heat exchanger.the maximum operating temp is 260 c and max pressure is 160 psi.
  • In reply to hashem ali:

    For crowded vessels, the DP/ERS is a valid solution for heat exchangers. A DP-Level specialist is far better suited to answer questions about DP/ERS as I am specialized on radar's. However: The radar does not necessarily need to be installed in a bridle - the main vessel may offer good installation points for the radar as well, as long as you have a nozzle at the top (or top side) of the vessel with "clear sight" down to the bottom (which indeed can be a challenge in a heat exchangers). Kind regards/Ingemar Serneby
  • Increase the coupling flange up to 3" or 4" (to minimize thermall error) and put a new transmiter with direct or remote seal (with minimum permitted capillary length) with the same seal flange. This is the recommended way if the previous measurement method was satisfactory (except draining).
  • In reply to leirbag:

    What did you mean by increasing coupling flange ?and your speech means that DP is better than radar?and my situation is the installed flange that at vessel is 2" CL300 and used for level transmitter wet leg configuration and i have already remote seal transmitter with smaller flange size than installed so what is the abillity to use this existing transmitter? And is it better to use remote seal transmitter with the same size of installed flange?
    Note: max oper. Temp. Is 260 c and max oper. Pressure is 160 psi
  • The discussion on which technology might work best for your application will require more information about your application to better understand what might work best for your needs. It might be best to discuss the details of your application with a local expert that can guide you to what will be best for you. Can I connect you with a local Emerson representative that can help you?
  • In reply to hashem ali:

    Install an adapter piece from 2"flange to 3"or 4" flange. Buy a new transmitter with direct or remote seal for the new flange with a special oil for your temperature specifications. A smaller flange size it's not a solution. If your problem is only the sludge draining, I recommend this easiest solution. I'm also using the radar and I believe the DP transmitter is a very simple and reliable solution.

  • In reply to leirbag:

    I want to ask about the reason of increase flange size, i can use 2" existing flange and order a new transmitter with the suitable liquid.Are Remote seal accurcy with sludge with be greater than Dp transmitter as i need to drain it daily or radar will the greatest accuracy.

    If we use non- contact radar in my case (shell and tube)without using bridle,the readings will be accurate or the bundle inside exchanger will affect the readings....

  • In reply to hashem ali:

    Fill fluids expand or contract with temperature changes, creating a volume change that is absorbed by the diaphragm seal and is seen as back pressure at the transmitter. This back pressure creates a shift in the transmitter reading. For symmetrical or balanced systems, this error is usually minimal due to the back pressure being equal on both sides. However, head temperature effect is still present .Seal temperature effects decrease as seal size increases. This is the reason I recommend 3" or 4" seal instead 2". Other factors that affect seal temperature effect include diaphragm thickness, seal type and size, capillary length and inner diameter. A good chosen pressure or DP transmitter has a max 0.05% from calibrated range base error . The total error will be specified by the new transmitter supplier. Radar is a more complicated solution (if is suitable for your application).
  • In reply to leirbag:

    Hi , can you please tell us more about your application and your general location? Great input coming in here from . , etc. Looks like the community can better help you pinpoint what solutions will work best for you if you are able to supply this info. Thanks!

    Best Regards,

    Rachelle McWright: Business Development Manager, Dynamic Simulation: U.S. Gulf Coast

  • In reply to Rachelle McWright:

    Dear eng.rachelle,
    I'm very glad to talk with you,
    simply,my aplication that i have heat exchanger (shell and tube) as shown at attached mechanical drawing (the related flanges of transmitter LIT1,2).And DPT is used to measure level(wet leg configuration).After capacity was increased, Sludge built up and as a consequence FWM and transmitter were blocked and need to drain daily.so i need answer clearly for the following questions:
    1-What is suitable action taken to solve this problem?
    2-what is the suitable supersede transmitter that we can use?
    3-why eng.leirbag need to increase the coupling flange?
    finally my company is worked at oil and gas field and located at egypt.
    regards,
  • In reply to hashem ali:

    Hi hashem ali,

    Do you have a way to access the top of the heat exchanger?  Because you don’t have a bridle, to consider a radar solution you will need a way to install the device on top of the heat exchanger that has a clear path to fluid.  

    To better answer your questions, I need some very specific information:

    Please provide your mechanical drawing to (nathan.stokes@Emerson.com) as I did not see it get posted here.

    Other application data I would need to evaluate your application would be:

    • Process temperature min and max (operating)
    • Ambient temperature min and max at your location
    • Process pressure min and max (operating)
    • Specific gravity or density of the fluid whose level you want to measure
    • Tap to tap distance

    You are currently using a 2” 300# flange correct? 

    Would you be concerned about build up inside of the flange connection?  You could consider an extended seal design that has a extension into the flange so that the diaphragm is flush with the inner vessel wall.  This will eliminate any potential for plugging.

    The others comments about flange size are valid.  This is because the diameter of a remote diaphragm seal has a big impact on the performace of the unit.  The larger the diameter of the seal, the better overall performance you can get from a system.  A 2” 300# connection is very common remote seal size and you can get good performance from it.  By providing the information above, I can calculate what the performance would be in your application and if a traditional system with capillary would be best or if Electronic Remote Sensors would be best.

    If you have the ability to add a radar measurement to the top of the heat exchanger, we can also provide you with information about that type of solution so you can evaluate the tradeoffs between a radar solution and a differential pressure based solution and what will be best for your application.

    Nathan

  • In reply to Nathan Stokes:

    Mechanical Drawing of H-3001 (1).pdf

    Dear nathan,
    good day,
    firstly,listed under-here all the parameter required:
    1-min process temp.=229 F
    max process temp.=425 F
    2-ambient temp. min=9 C
    ambient temp. max=45 C
    3-process pressure min=88.3 psig
    process pressure max=185 psig
    4-density of condensate=0.7848 g/cm3 at 288 K
    5-Tap to tap distance(flange to flange)=130cm
    6-URV=-33 inH2O
    LRV=-63 inH2O
    if you need any further data don't hesitate to contact me,
    can you please also evaluate the tradeoffs between a radar solution and a differential pressure based solution?

  • In reply to hashem ali:

    If there any reply for my input
  • hashem ali

    Thank you for the detailed information. I investigated pressure based level options based on your application. I considered both Electronic Remote Sensors (ERS™) Systems and traditional capillary based systems. Because of the small tap to tap distance, a tuned-system™ assembly would be recommended. A tuned-system assembly uses a direct mount seal on the high pressure tap at the bottom of the vessel and a seal with capillary up to the top tap. More information on different types of pressure and remote seal seal level systems is available at the link below:

    www2.emersonprocess.com/.../00840-1400-4801.pdf

    If you stay with the 2” size flange connections, a tuned-system assembly accuracy would be in the range of +/-1 to 2.5 inH2O over the entire temperature range. If you were able to increase the size fo the connection to a 3” flanged connection, the performance over the entire operating range could be 0.6 inH2O. As mentioned previously, performance improves with large diameter remote seals. Below are the complete model numbers I assumed for the 3” connection version.

    3051CD2A22A1AS2
    1199WLAB4AFFW71DA00
    1199MLD57AFFW71DA00

    You can use the following product datasheets for more information on those models. Note that the low pressure 1199 system uses 3.5m of capillary which is more length than you need, but it is intentional as the added fill fluid in the longer length of capillary helps to provide better “tuning” of the system for better overall performance.

    • 3051 PDS: www2.emersonprocess.com/.../00813-0100-4001.pdf
    • 1199 PDS: www2.emersonprocess.com/.../00813-0100-4016.pdf

    My focus is on pressure based level solutions, but radar is certainly another viable solution for this application. Radar requires a top-down measurement, so you would need to have a way to access the level from the top of the vessel or would need to add a bridle to the existing 2”flanged connections. Radar directly measures the fluid in the vessel. A radar solution could be very accurate and could have accuracies in the ± 0.2” range or perhaps better. Radar does require more configuration during the installation phase, but we have a software tools are available to make that configuration easy. Ingemar Serneby can add additional details or suggest a radar model for you to consider.

    Hope this helps, let me know if anything is unclear.

    Nathan