×
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

crude oil Tank Vent

crude oil Tank Vent

crude oil Tank Vent

(OP)
We have dia: 92 m, heigth:16 m  floating roof crude oil storage tank.

Oil has escaped from the  vents (located on roof) during filling and emptying operation of the tank. At first oil starts to pass from the vents, then after oil passing stops.

Could anyone indicate a reason for this.

Have you ever come accross such a problem.

Thanks in advance

saliba

RE: crude oil Tank Vent

Do you mean oil is escaping from the vacuum vent on the floating roof? If so, I would suspect the floating roof is hanging up somewhere.  Maybe the shell has a deformity?

  What is the tank level when this happens?

RE: crude oil Tank Vent

In addition of what Khardy said, check the wheels of the roof ladder may be during the filling and the emptying of the tank they got stuck on wheel  guides impeaching or creating resistance to the normal roof movement.


luis marques  

RE: crude oil Tank Vent

(OP)
yes oil is escaping from the vacuum vent on the floating roof. we check that, the roof is not hanging or stuck anywhere.

escaping occurs at first movements.  

RE: crude oil Tank Vent

For sure you must have any prison impeaching the free tank roof movement, due to lack of flexibility of pipe drain, gage pole prison, or leaking pontoons. If you are real confident that the tank roof is not stuck anywhere, another possibility is bad vacuum vents design. Please note:


“Filling and emptying a storage tank creates positive and negative pressures inside the tank. To fill a tank, air and vapors within the tank must be pushed out developing an internal tank pressure slightly above atmospheric pressure. For this reason, tanks are designed to withstand an internal pressure of 2.3 kPa. To empty a tank, the reverse occurs requiring air to enter the tank, developing an internal tank pressure slightly below atmospheric pressure. For this reason, atmospheric tanks are designed to withstand a vacuum of 0.689 kPa. Ambient pressure and temperature changes may also produce a slight pressure or vacuum within the tank. To accommodate this air movement, vents are provided to prevent the tank from exploding or imploding. Normal vents are sized in accordance to Article 4.3.4.1. or API Standard 2000, "Venting Atmospheric and Low Pressure Storage Tanks," Table 1, but in no case should the vent size be less than 30 mm nominal inside diameter”


Luis marques

RE: crude oil Tank Vent

Luis,
From where did the quoted text come?  It looks like a project spec statement.  I do not recognize it as coming from an API document.

Joe Tank

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