×
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

The use of float pans in bulk fuel storage tanks

The use of float pans in bulk fuel storage tanks

The use of float pans in bulk fuel storage tanks

(OP)
Have a DoD requirement to use float pans in three bulk fuel storage tanks. Is there any way to meet the intent of the float pans without using them. The reason I am asking is the sub contract has built the tanks without installing the float pans. I am trying to avoid having them tear them open and install them. Thanks in advance! V/r Dan

RE: The use of float pans in bulk fuel storage tanks

Can you define"float pans"

Do you mean floating suction?

Needs more data but to be honest I doubt it. If the client wants them the client gets theM.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: The use of float pans in bulk fuel storage tanks

(OP)
Thank you for responding! The float pan is a honeycomb design that floats on the surface of the fuel (oil)it is meant to reduce the amount of vapor build up. Thanks again!

D

RE: The use of float pans in bulk fuel storage tanks

As far as I know, there is no need for an internal floating roof ( which I believe is what you call an internal floating pan) on regular diesel storage tanks, unless these are located in some hot climes where external air temps can be >55degC for several hours in the day. See page 20 and fig 9 in the attachment which discusses DoD requirements.


https://www.cedengineering.com/userfiles/Intro%20t...

RE: The use of float pans in bulk fuel storage tanks

But how on earth had the sub contractor not built something as fundamental as a floating roof!!

Forgetting a nozzle or a flange the wrong size maybe, but an internal roof??

I know what I would say if I was the client. I wouldn't even think about getting to wriggle out of this.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: The use of float pans in bulk fuel storage tanks

(OP)
Thank you both for the input. The tanks are located in the middle east. and are considered mission critical. Based on your input I will hold them to the fire to put them in. Their reasoning was that the local country fuel provider does not require them so they did not put them in

RE: The use of float pans in bulk fuel storage tanks

I'm not absolutely sure what these are (but it sounds like an internal floating roof), but that sounds like a pretty lame excuse to me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: The use of float pans in bulk fuel storage tanks

Think it has to do with difference of opinion between the DoD and the subcontractor on the number of hours a day at greater than 55degC to make the tank contents rise in temp to 55degC. Some ways of reflecting away solar radiation would be to use reflective aluminum paint / adding on external insulation. Internal floating roofs arent all 100% reliable either.

RE: The use of float pans in bulk fuel storage tanks

(OP)
Agree. But due to the tactical nature of the asset it needs to remain the color scheme of the current design. The sub basically relied on the fact that the host nation did not require the pans. But like safety regs, mission critical requirements are written due to a failure during a critical event. I was trying to find another path for them to take without having to rip the tanks apart but there does not seem to be any other way to meet the intent of the pans. I am all about requirements but not blind to the fact that the intent or function of the requirement can be met by alternate means. If we go for a relief on the use of the pans without an alternate plan I would have to get concurrence from the end user and I do not see that happening.

D

RE: The use of float pans in bulk fuel storage tanks

It seems unusual that this no one in your organisation noticed non compliance to this basic requirement up till now. Having to rip up the roofs to install these IFRs' now is going to be painful not only for the sub, but for people in your company too, since both CAPEX and schedule delays will be unavoidable. Another suggestion to mitigate the risk of operating this tank at >55degC, with lower impact on cost and time than internal floating roofs (and IF the client is willing to accept this deviation to design standards), would be to acknowledge the increased volatility of diesel at these temperatures, redo the hazardous area classification around the tank vents and respecify any electrical / instrumentation around these vents to suit. A redesign of the free vents on this tank may also be required.

RE: The use of float pans in bulk fuel storage tanks

The DoD has a thing for honeycomb internal floating roofs even though they represent outdated technology and are less strong, less safe, have higher emissions and have more maintenance issues than other versions of full-contact IFRs. IFRs are typically not needed for VOC containment and fire protection in typical jet or diesel tanks unless the storage conditions or facility emissions profile requires them. They do help for product contamination - water and dust. You only have to make a relatively small hole in the tank shell or roof to put the parts inside. Not really a big deal or very large cost, possibly expected anyway if the IFR was going to be installed after the hydrotest.

RE: The use of float pans in bulk fuel storage tanks

If this has been resolved, great, but most IFR's can be retrofitted via the manway. We have done quite a few, full contact IFR's and pontoon style.

Pontoon style a minnumen of 800mm manway, for full contact an entrance of 400 x 1400 is needed.

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

eBook - Mastering Tolerances for Machined Parts
When making CNC machined parts, mastering tolerances can be challenging. Are general tolerances good enough? When does it make sense to call out for tighter tolerances? Do you need a better understanding of fits, datums, or GD&T? Learn about these topics and more in Xometry's new e-book. Download Now
eBook – How to Choose the Correct Corrosion Testing Method
When designing a metal component, engineers have to consider how susceptible certain alloys are to corrosion in the final product’s operating environment. In a recent study by NACE (National Association of Corrosion Engineers), it was estimated that the direct and indirect costs of corrosion in the United States is approximately 6.2% of the GDP. In 2016, that cost exceeded $1 trillion dollars for the first time. Download Now

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