Dear All
Vacuum Box is used to test for pin holes on the weld as well as bottom plates. Plate damage is common in construction of the Tank due to falling objects or sparks made by welders. Floating roof tanks have a lot of pantoons which are also leak tested by Vacuum Boc and air leak testing. The Roof lap- joints are also tested by Vacuum Box for the same reason. It is not meant for welds only and can cover plates as well. I have used it for leak detection of pontoons of a floating roof while resting on its support. DPT or MPI are meant for a limitted area for their cost as explained by other friends.
Shell fillet weld to the annular plate is also tested normally by special Vacuum Box (to fit the 90 angle) and in its absence a penetrant materials such as diesel oil is applied to the corner weld from inside surface and a white powder( not commercial developer) sprayed to the weld from outside, giving them 24 hours to detect the hole or crack. DP or MPI is used when such method detects a defect.
Hope this helps
-----materials-welding@googlegroups.com wrote: -----
To: materials-welding@googlegroups.com
From: M S
Sent by: materials-welding@googlegroups.com
Date: 05/07/2012 10:12AM
Subject: [MW:14200] API 650 - Vacuum box test Vs PT/MT(Penetrant Test/MPI)
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
From: M S
Sent by: materials-welding@googlegroups.com
Date: 05/07/2012 10:12AM
Subject: [MW:14200] API 650 - Vacuum box test Vs PT/MT(Penetrant Test/MPI)
Please provide technical support:-
What is the difference between Vacuum box test(for leak detection) and PT(for surface discontinuity detection)?
PT can detect all the surface discontinuity as well and MT can detect surface and slightly subsurface discontinuity also, but why API 650 prefers Vacuum box test instead of PT for Carbon steel-tank bottom plate welding?
--To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
This email and any attached files ("Message") may contain confidential and/or privileged information. It is intended solely for the addressee(s). If you receive this Message in error, inform the sender by reply email, delete the Message and destroy any printed copy. Any unauthorized use, distribution, or copying of this Message or any part thereof is prohibited. Emails are susceptible to alteration. Neither Technip nor any of its affiliates shall be liable for the Message if altered or falsified nor shall they be liable for any damage caused by any virus that might be transmitted with this Message. -- To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
No comments:
Post a Comment