Steam/Condensate Line Failure 1

[billNYE]

Return condensate lines from the equipment using the steam to the condensate flash drum is seeing regular failures in many elbows and fittings. I was wondering about any potential causes for these fialures within the condensate lines.
We believe it to be a combination of high velocities with two phase flow that is causing erosion. If velocity is the problem, is there any standards for the Max flow rate you can have in condensate lines
The Plant in question is an upgrader that has been running for approx 20 years with increased production of oil and no improvement done on the steam and condensate system. (if that helps any)

 

[21121956]

Hello everybody:

billNYE, a good start for you would be to read the documents of Spirax Sarco in this site:

http://www.spiraxsarco.com/resource...-recovery/sizing-condensate-return-lines.asp.

Good luck!

 

[stanweld]

You could have CO2 corrosion or flow assisted corrosion/errosion, assuming carbon steel piping. If so you may cionsider replacement of carbon steel with A-335 P11 or P12 alloy.

 

[davefitz]

There may have been an outlet flow restirction orifice tha eroded or was removed- if the outlet fow restiction is modified, then the condensate flow increases and you will also flash to 2 phase flow further upstream in the pipe.

To limit flashing to only the outlet section, it may help to have an outlet flow resticion orifice or capillary tube.

 

[786392]

CO2 Corrosion in condensate systems is killing/highly damaging;

although most usually considered 'innocent' or even "non-existent".

Best Regards
Qalander(Chem)

 

[MJCronin]

Condensate return systems are disposables.... Carbonic acid

http://www.infrastructure.alberta.ca/Content/docType306/Production/TechPres26.pdf

The proper water treatment will help...lots of people will sell you chemicals

You should be happy that you got 20 years out of the system

Was yours Schedule 40 or 80..???

Section by section, replace what exists with a schedule 80 carbon steel system.

It will outlast you..

-MJC

 

[fortmceng]

Steam should not be routed to condensate flash pot only condensate. Failures at elbow is common problem in overloaded condensate system where steam traps are not functioning properly or steam line connected to condensate system by mistake. You could try stellite coated elbow. It should give you some relief if you choose not to correct the root cause.

 

[billNYE]

Thank you everyone for your input. I am a student currently on internship and all information has been helpful. thanks again