Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Steam sensing lines plugging

Steam sensing lines plugging

Steam sensing lines plugging

The client has differential pressure flow and pressure transmitters on a steam line that are plugging up with ammonium bicarbonate. The sensing lines are tubed to condensate pots then onto the transmitters. The condensate pots enable precipitation where the ammonia precipitates out of the gas phase as ammonium bicarbonate then plugs up the lines. Due to low budget and time they need to use the same style of measurement but redesign it to work. Their main idea is to remove the condensate pots, use root valves that take off below the process line, shorten the impulse lines and tube with a slop down to the transmitters then fill the impulse lines with Triethylene glycol that has a boiling point of 285°C.

Need your thoughts on this or any better way of doing it with the same measuring concept.


RE: Steam sensing lines plugging

you might consider use of continuous purging, though it carries it's own problems

RE: Steam sensing lines plugging

hacksaw, good idea but you are right in more problems. They don't need anymore maintenance problems then what they already have with the ammonium bicarbonate and are not willing to change the system or spend a ton for added features. We will just have to see how this present idea will work.

RE: Steam sensing lines plugging

The issue I've heard of is that over time, condensate dilutes the fill fluid so the SG/density in the impulse lines change, resulting in a shifting zero/offset/DP.

RE: Steam sensing lines plugging

I just saw in passing a type of level measurement without impulse lines.
At the low level a transmitter used a direct mounted pressure transducer.
A high mounted pressure transducer sent an electrical signal to the transmitter.
The transmitter compared the two pressure signals and outputted the difference.
Loop powered 4-20 ma.

"Why not the best?"
Jimmy Carter

RE: Steam sensing lines plugging

You say the sensor is tubed to the condensate pots, why is that?
The condensate pots should be as close to the orifice plate as possible with 1/2 pipe connections that way they operate just below line temperature and the steam won't condense out so fast.

RE: Steam sensing lines plugging

waross: The pressure sensing element needs to be able to handle 300 degrees C plus temperatures. That is why they are tubed away from the process to cool down the process temp as there is not a sensing element that can handle such extreme heat.

roydm: The condensate pots are where the problem starts. When the steam condenses out so does ammonium bicarbonate which then plugs the lines. This seems to happening within the pots and that is why they are getting rid of them.

On top of it all these guys do not want to spend any money to upgrade their transmitters or change the way they are measuring it with another type of flow meter.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close