×
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

ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

(OP)
Dear Gents,

As per our tank foundation drawings we are supposed to install an asphalt impregnated board at the bottom of tank bottom plate.Since this asphalt board is in touch with the tank bottom plate Is there any chance to catch fire on it while doing the POST WELD HEAT TREATMENT of the weld joints of tank? Moreover this while doing welding of the plates is there any chance to get fire because of the spatters of welding? If it catches fire is there any other alternative for this? Is there any other practices to avoid catching of fire during construction of tank. Kindly advice. Thanks in advance

Rency isac

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

Pad products have been used under floors that were then welded in place. Pad around the perimeter of a tank can be slipped in after welding of that area is completed. I can't imagine how the pad would survive efforts to stress-relieve the plate resting on it, though.

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

I do not understand why this is a problem....

Why do the thin floor plates in an API-650 tank require post-weld heat treatment ?

Please do not answer "that is what the client requires in his specification".....

What is the specific tank floor material, thickness, and weld type for your particular tank ?

Who is supplying this board ? Have you contacted them ??

Is this the first tank for you, where asphalt impregnated board is used ?

MJCronin
Sr. Process Engineer
Venture Engineering & Construction
www.VentureEngr.com

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

MJCronin,

PWHT of the complete tank is often specified for caustic storage. Whether or not it actually prevents stress corrosion cracking in the floor seams may be subject to debate.

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

I assumed either the vertical shell welds or the entire tank was to be stress-relieved, and either would heat the attached bottom also.

The board in question is usually a cane-fiber asphalt-impregnated expansion joint material. It is intended for use in concrete, not under tanks, and it is unlikely the manufacturers would have data on high-temperature applications of it. Maybe a maximum temperature, which is likely less than 1200 degrees.

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

I assumed either the vertical shell welds or the entire tank was to be stress-relieved, and either would heat the attached bottom also.

The board in question is usually a cane-fiber asphalt-impregnated expansion joint material. It is intended for use in concrete, not under tanks, and it is unlikely the manufacturers would have data on high-temperature applications of it. Maybe a maximum temperature, which is likely less than 1200 degrees.

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

(OP)
Dear Gents,

We are supposed to do the PWHT where the flush type clean out man hole is coming. This is as per API 650. For details of the location of asphalt impregnated board please find the attached drawing. Datasheet of the asphalt impregnated board is also attached along with this thread for your reference. Kindly help me to resolve this problem.

RE: ASPHALT IMPREGNATED BOARD BELOW TANK PLATE AS PER API 650

Unless you are PWHT the entire tank, the flush cleanout must be shop PWHT. Per 650 5.7.4.1 All flush-type cleanout fittings and flush-type shell connections shall be thermally stress-relieved as an
assembly prior to installation in the tank shell or after installation into the tank shell if the entire tank is stress-relieved. This is a pretty big tank to PWHT the enter tank. However, if you are PWHT the entire tank in the field then you have a combustible issue and the best idea I have seen is to lift the tank after PWHT to install the fiberboard. You may also have an issue with heating the foundation and especially the HDPE Liner, the telltale pipe, the polysulfide sealant, etc.

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