×
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

API 620 or API 650?

API 620 or API 650?

API 620 or API 650?

(OP)
We are currently designing a number of tanks in Asia which store chemicals that require to be kept at temperatures equal to or below 15°C (60°F) to prevent polymerization of the stored products. Note that the average ambient temperature at this site is around 30°C (85°F).

To maintain product temperatures of 15°C (60°F) the tanks will be cooled via jet mixing systems that route the cycling product through shell and tube type heat exchanger, refridgeration system before it is returned to the tank. Note that Cooling bands will not be installed around the tank.

The minimum design temperatures of the cooled product is - 15°C (5°F). The tanks will be insulated. Please note that these tanks will not be subject to thermal shock or significant variations in temperature


My question is - can these tanks be designed to API 650 or do I need to design to API 620 (Appendix R)- bearing in mind that you can design a tank to API 650 in Canada with a much lower design temperature than what we are using.

Thanks in advance
Sam
 

RE: API 620 or API 650?

We routinely design storage tanks in Western Canada to API 650 with design temperatures far lower than this.  The last project I had some involvement with was an API 650 tank with a design minimum temperature of -32 C.

Typically, we would select materials with inherent toughness (fully killed, fine grain practice, etc) to avoid the cost of impact testing. However, make sure that the material you select is rated by API 650 to the design temperature you require.

RE: API 620 or API 650?

Assuming the tanks are not pressurized beyond the App. F limits, I would go with API-650, making allowances for the temperature.

RE: API 620 or API 650?

(OP)
Thanks very much for your replies, I will design to 650 taking into account design metal temp during steel selection.

These tanks will be fitted with Nitrogen blanketing systems, but the design pressure will not exceed the limiys in App F.

Regards
Sam

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