where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -
1058 views
Technical Discussions
Dent McIntyre
Consultant, NDE Manager NDELevel III/3
NDT Consultant, Canada, Joined Nov 1998, 250

Dent McIntyre

Consultant, NDE Manager NDELevel III/3
NDT Consultant,
Canada,
Joined Nov 1998
250
00:47 Mar-29-1999
Penetrant Test of vessel under pressure

A vessel is under Helium pressure at 100 PSI for the purpose of performing a Helium Leak test.
A tiny Inconel weld on the vessel needs to be PT inspected but was not done prior to pressurizing.
What effect will this have on the penetrant test?


 
 Reply 
 
S.V.Swamy
Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex , India, Joined Feb 2001, 787

S.V.Swamy

Engineering, - Material Testing Inspection & Quality Control
Retired from Nuclear Fuel Complex ,
India,
Joined Feb 2001
787
09:45 Aug-16-2002
Re: Penetrant Test of vessel under pressure
Pressurisation of the vessel will have a tendency to slightly expand the vessel, thus there will be a tensile stress on the outer surface. This will slightly magnify the size of any discontinuity that may be present. So, the best course is to 'retest' the same weld after the pressure test is completed and the internal pressure removed, before attempting to 'size' the discontinuity and apply the specification for acceptance and or repair.

: : A vessel is under Helium pressure at 100 PSI for the purpose of performing a Helium Leak test.
: : A tiny Inconel weld on the vessel needs to be PT inspected but was not done prior to pressurizing.
: : What effect will this have on the penetrant test?
: ..
.



 
 Reply 
 
rodney fordham
rodney fordham
03:55 Aug-16-2002
Re: Penetrant Test of vessel under pressure
:A partial thickness crack on the outside of a pressure vessel wall opens slightly when the internal pressure is applied. The more sensitive interferometric techniques reveal that the vessel bulges a little in the vicinity of the crack. Does anyone know what the relative importance of internal and external partial thickness cracks is? Clearly the external cracks are more weakening than internal?
====================
: Pressurisation of the vessel will have a tendency to slightly expand the vessel, thus there will be a tensile stress on the outer surface. This will slightly magnify the size of any discontinuity that may be present. So, the best course is to 'retest' the same weld after the pressure test is completed and the internal pressure removed, before attempting to 'size' the discontinuity and apply the specification for acceptance and or repair.
.
: : : A vessel is under Helium pressure at 100 PSI for the purpose of performing a Helium Leak test.
: : : A tiny Inconel weld on the vesselneeds to be PT inspected but was not done prior to pressurizing.
: : : What effect will this have on the penetrant test?
: : ..
: .
.



 
 Reply 
 
Dent McIntyre
Consultant, NDE Manager NDELevel III/3
NDT Consultant, Canada, Joined Nov 1998, 250

Dent McIntyre

Consultant, NDE Manager NDELevel III/3
NDT Consultant,
Canada,
Joined Nov 1998
250
05:36 Aug-19-2002
Re: Penetrant Test of vessel under pressure
Pressure inside a vessel especially (helium)will inhibit the capillary action of the penetrant in entering leaks. The thru wall leak may not be detected with the penetrant test.
Furthermore, penetrant could also plug a tiny leak and make it undetectable with the helium test.

This information comes from a recent experience of a vessel similar to the one described.
For more information e mail me directly.


: :A partial thickness crack on the outside of a pressure vessel wall opens slightly when the internal pressure is applied. The more sensitive interferometric techniques reveal that the vessel bulges a little in the vicinity of the crack. Does anyone know what the relative importance of internal and external partial thickness cracks is? Clearly the external cracks are more weakening than internal?
: ====================
: : Pressurisation of the vessel will have a tendency to slightly expand the vessel, thus there will be a tensile stress on the outer surface. This will slightly magnify the size of any discontinuity that may be present. So, the best course is to 'retest' the same weld after the pressure test is completed and the internal pressure removed, before attempting to 'size' the discontinuity and apply the specification for acceptance and or repair.
: .
: : : : A vessel is under Helium pressure at 100 PSI for the purpose of performing a Helium Leak test.
: : : : A tiny Inconel weld on the vessel needs to be PT inspected but was not done prior to pressurizing.
: : : : What effect will this have on the penetrant test?
: : : ..
: : .
: .
.



 
 Reply 
 

Product Spotlight

FAAST-PA! OEM Patented phased Array for high speed UT inspection

Multiangle, Multifocus, Multifrequency, Multibeam. Instead of stacking UT electronics and having m
...
any PA probes, FAAST-PA is able to transmit all delay laws within ONE single shot in Real time.
>

IntraPhase Athena Phased Array System

The Athena Phased Array system, manufactured by WesDyne NDE Products & Technology, consists of a pha
...
sed array acquisition system and PC running IntraSpect software. A PC is used to perform acquisition, analysis and storage of the data. System hardware is capable of operating up to four data sets with any combination of phased array or conventional UT probes. NOW AVAILABLE IN 64-64 CONFIGURATION.
>

Lyft™: Pulsed Eddy Current Reinvented

PEC Reinvented—CUI Programs Redefined Corrosion under insulation (CUI) is possibly the greatest u
...
nresolved asset integrity problem in the industry. Current methods for measuring wall thickness with liftoff, without removing insulation, all have severe limitations. Eddyfi introduces Lyft — a reinvented, high-performance pulsed eddy current (PEC) solution. The patent- pending system features a state-of-the-art portable instrument, real- time C-scan imaging, fast data acquisition with grid-mapping and dynamic scanning modes, and flexibility with long cables. It can also scan through thick metal and insulation, as well as aluminum, stainless steel, and galvanized steel weather jackets. Who else but Eddyfi to reinvent an eddy current technique and redefine CUI programs. Got Lyft?
>

IRIS 9000Plus - Introducing the next generation of heat exchanger inspection.

Representing the seventh generation of the IRIS system, the IRIS 9000 Plus has nearly 200 years of c
...
ombined field inspection experience incorporated in its design. This experience combined with a strong commitment to quality and a history of innovation has made Iris Inspection Services® the undisputed leader in IRIS technology.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window