Pressure Transmitter ( Air pressure transmitter and Lpg pressure transmitter valu Ex)

Hello Everyone , Hope you all are well and safe sound!

I'm looking solution for the pressure transmitter which are installed in Blender or Lpg/ Air mixer - Two pressure transmitter are installed in blender one for Air, Air pressure transmitter while another for LPG, LPG pressure transmitter , both show S971 adjustment and high value exceeded from normal working range to 5.55 kg/cm2, the normal working value is below 3.60 kg/cm2, due to this high value Programmable logic controller( PLC ) Alarm also ON, So how it will be troubleshoot to come back the value to original normal working range ? Please share knowledge about this issue ?
Note : A constant percentage of Air is mixed with the required amount of LPg to creat Synthetic natural gas!
Liquid Lpg must must ist be converted to gaseous state with the use of vaporizer .
The super heated Lpg vapor is then blended with air supplier from n air compressor to a specific ratio creating synthetic natural gas. This mixing occur in belender/ Lpg air mixer !

Can you post a sketch of the process?


Does the PLC have a way to change the pressure e.g. open a valve, control the speed of an air compressor or LPG pump?


For me, air + LPG + heat (vaporizer) + high pressure => get everyone out of the building ASAP!

There are two possibilities, the sensors are out of calibration or faulty, or it really is at high pressure, if you are not experienced in fault finding Then I suggest you take DR's advice, this is a critical process not to be messed with without experience.

Welcome to the forum.

as already pointed out, the sensors are out of calibration.
they are faulty.
the sensors are not designed for this application and are giving incorrect data.
the plc program (assuming a plc) does not have the inputs scaled correctly.
the display (or other system) does not have the data scalled correctly.
you actually have high pressure.


please get an experienced company to test and verify calibration, as this is your first post, I am going to error on the side of caution and say to get help. being a flammable gas, mistakes will be very costly.
james

It's too easy to blame the messenger.


There is a very low probability of 2 modern pressure transmitters failing or going out of calibration at the same time.



That's assuming no one has messed/played with with the range setup.



I'm putting my money on a process problem.



I think the plant needs a process engineer who can read a P&ID to get out there figure out why the pressure is twice what it should be.

parky said:

There are two possibilities, the sensors are out of calibration or faulty, or it really is at high pressure, if you are not experienced in fault finding Then I suggest you take DR's advice, this is a critical process not to be messed with without experience.

Click to expand...

I observe ! When Gas is forming in Blender that time the value in Pressure Transmitter (PT) is in normal working range .
When Gas is formed the value becomes higher higher in the pressure Transmitter (PT) gradually and slowly .

danw said:

It's too easy to blame the messenger.


There is a very low probability of 2 modern pressure transmitters failing or going out of calibration at the same time.



That's assuming no one has messed/played with with the range setup.



I'm putting my money on a process problem.



I think the plant needs a process engineer who can read a P&ID to get out there figure out why the pressure is twice what it should be.

Click to expand...

Hello , Hope everything is well and safe sound .
I observe ! When Gas is forming in Blender that time the value in Pressure Transmitter (PT) is in normal working range .
When Gas is formed the value becomes higher higher in the pressure Transmitter (PT) gradually and slowly .
Really helpful ,
Many thanks

parky said:

There are two possibilities, the sensors are out of calibration or faulty, or it really is at high pressure, if you are not experienced in fault finding Then I suggest you take DR's advice, this is a critical process not to be messed with without experience.

Click to expand...

James Mcquade said:

Welcome to the forum.

as already pointed out, the sensors are out of calibration.
they are faulty.
the sensors are not designed for this application and are giving incorrect data.
the plc program (assuming a plc) does not have the inputs scaled correctly.
the display (or other system) does not have the data scalled correctly.
you actually have high pressure.


please get an experienced company to test and verify calibration, as this is your first post, I am going to error on the side of caution and say to get help. being a flammable gas, mistakes will be very costly.
james[/QUOTE

Truly appreciate ,
i am glad i got this forum.
thank you !

Click to expand...

drbitboy said:

Can you post a sketch of the process?


Does the PLC have a way to change the pressure e.g. open a valve, control the speed of an air compressor or LPG pump?


For me, air + LPG + heat (vaporizer) + high pressure => get everyone out of the building ASAP!

Click to expand...

i just observed, it just shows a high value .
the process is normal .
Many thanks !