×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

A 335 grade P5 +Any chance of having it at 745 C temperature?

A 335 grade P5 +Any chance of having it at 745 C temperature?

A 335 grade P5 +Any chance of having it at 745 C temperature?

(OP)
Dear Coleagues,

We have a consult from a Refinery previewing a De-cocking procedure. Their systems are design for about 480 C. The basic material is A 335 grade P5.  The De-cocking operation is arround 710C operation - 745 C design.

This is far beyond the temperature tabulated in ASME B31.3 allowable stress. According to that the maximum temperature for that material is 650 C.

The operation will last 10 hours.

Does anybody knows some paragraph or statament on B31.3 which could allow this use?

Regards,
Hansito

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

Its 700 ºF

**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

(OP)
No BigInch

First I thought the same, but it is really Degree C.


Regards,
Hansito

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

There are allowances in the Codes for abnormal temperature/pressure excursions providing the yield stress is not passed; however, a 10 hour process would not fit into this category.

I2I

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

Right.  I was on the wrong page.
I see it is 1100F (so 593 C) is the limit and its a very very low stress allowable too.

No, it is as I2I says.

Can you reduce operating pressure during that time?  

**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

These actions are common Coker practices. Repairs are also common. Replacement starts the cycle anew.

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

(OP)
It is an existing furnace, I believe it is operating for more than 20 years, at arround 480 degree C.

What I undertood (We are still in the process of receiving information) is that now they need a De cocking  operation, which is (as far as I understand) a kind for dust cleaning.

They just asked  us about a possible new Piping Stress Study for the new temperature, but when I saw the data and the basic Material I think to myself that if your out the temperature code limits there is no much we can do about stress. I agree that 10 hour is too much time to consider the extras previewed on the code.

Thank you very much for all responses, I really appreciated them and I will keep struggling with this. If this come to a techinical reasonable end I will included in here, and please if someone more has more information, opion or similar experience let me know.

Regards,
Hansito

RE: A 335 grade P5 +Any chance of having it at 745 C temperature?

For that material P5 the decoking procedure with steam air the skin temperature of pipes shall not be more than 650ºc.

In API STD 530 the limiting design temperature for A335 P5 is also 650ºC.

If they are afraid of tube stress induced by the temperature process of decoking with steam air, instead they can do a mechanical decoking with pigs

Please go to

http://www.cokebusters.com/


Luis marques
    
 

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!


Resources