NOTICE

Forums are temporarily disabled while we are working on a new login procedure.

When migrating the old forums over to our new forums we were unable to retain the identity of the authors, so the old posts will show up as "anonymous". All NEW posts will show up credited to their authors. So please participate and share knowledge just as you have in the past.

You must log in if you are an existing user or register if you are a new user in order to contribute to the discussions.

Discussion Forums - The Hendrix Group
HomeHomeDiscussionsDiscussionsOil Refinery Co...Oil Refinery Co...FLOATING ROOF TANK -- PAINTINGFLOATING ROOF TANK -- PAINTING
Previous
 
Next
New Post
8/19/2006 9:00 AM
 
Our Gas Processing Plant is under construction. We have 95 K cu. m. floating Roof Tanks for Condensate storage having 78 m dia. x 22.4 m hieght. The Floating roof is double deck. As per project specification top side of upper deck and under side of bottom deck is to applied epoxy paint dft 350-450 microns. The primary roof seal consists delta seal foam pieces wrpped over by scuff band of synthetic rubber. The Tank is to be hydro tested with sea water after installing the roof seal arrangement. The question is: 1) should we allow painting of the top side of the upper deck (non-wetted parts) before the hydro test? What are the risks involved? 2) the under side of the bottom deck (wetted part) is required to be painted after hydro test. Also if painting is to be done after hydro test, how do we protect the roof seal arrangement? i request members to contribute their views on the subject.
 
New Post
8/21/2006 9:00 AM
 
Prakash To get 350-450 micron (DFT), your paint specification would definitely call for sand-blast or shot blast cleaning to Sa 2.5 / Sa 3.0 for both top and bottom decks. If Sand blast cleaning is specified and insisted contractually in specification, you have to complete the painting both wetted and non-wetted parts before seals are fixed. (Chances of abrasive blast cleaned sand may get into delta seal rubber and may affect the seal performance if blast cleaning is done after HT). Without proper blast cleaning, 350-450 micron epoxy paint application (epoxy system) would not be effective for both top deck and bottom decks. Epoxy paint system will fail in a short time. For top deck there may not be any limitation to do paint application after HT but you have to recognize that abrasive blast cleaned sand may affect seal life if seals are installed before blast cleaning (if paint application is done with blast cleaning after HT). Final hydro test can be attempted after painting is completed with new seals fixed before hydro test. You have to also recognize that at least the bottom and sides of the tanks are to be thoroughly flushed with fresh condensate or fresh water aftre hydro test (if hydro test is done with sea water due to the huge quantity needed for HT). Condenstae tanks with uncleaned salt deposit or chlorides may give problems in process condensates in service. Thorough flushing of the tank with salt water residue would be needed. Trust this helps you C.V.Srinivasan Nishi Engineers Pvt Ltd India August 22,2006 E-mail: nishi@vsnl.com >Our Gas Processing Plant is under construction. We have 95 K >cu. m. floating Roof Tanks for Condensate storage having 78 >m dia. x 22.4 m hieght. The Floating roof is double deck. As >per project specification top side of upper deck and under >side of bottom deck is to applied epoxy paint dft 350-450 >microns. The primary roof seal consists delta seal foam >pieces wrpped over by scuff band of synthetic rubber. The >Tank is to be hydro tested with sea water after installing >the roof seal arrangement. > > The question is: > >1) should we allow painting of the top side of the upper >deck (non-wetted parts) before the hydro test? What are the >risks involved? >2) the under side of the bottom deck (wetted part) is >required to be painted after hydro test. > >Also if painting is to be done after hydro test, how do we >protect the roof seal arrangement? > >i request members to contribute their views on the subject.
 
New Post
8/21/2006 9:00 AM
 
Thanks for the reply, Srinivasan. Yes grit blasting to Sa3 is required before epoxy painting. Therefore we have decided to perform the hydro test without fixing the seal. On completion of HT, we will undertake painting and seal will be fixed just before taking tank into service. your reply was of great help.
 
Previous
 
Next
HomeHomeDiscussionsDiscussionsOil Refinery Co...Oil Refinery Co...FLOATING ROOF TANK -- PAINTINGFLOATING ROOF TANK -- PAINTING


  

News

With a little delay, our Calculation of Ammonium Salt Deposition Temperatures...read more
Our sulfidic corrosion calculators are now available at hghouston.com/calcula...read more

Stay Current

Sign up for our quarterly newsletter

covering updates on corrosion

Sign Up