where expertise comes together - since 1996

Web's Largest Portal of Nondestructive Testing (NDT)
Open Access Database (Conference Proceedings, Articles, News), Exhibition, Forum, Network

All Forum Boards
Technical Discussions >
UT in ASME B31.3 High Pressure Piping
Career Discussions
Job Offers
Job Seeks
Classified Ads
About NDT.net
Articles & News

13:56 Dec-10-2009

Carlos Correia

R & D, - -
Joined Oct 2008
UT in ASME B31.3 High Pressure Piping

Hello Brothers of NDT World:
As many knows, the ASME B31.3 code (2006 version), doesn’t allow the substitution of RT with UT applications for inspection of weld joints in pipes considered as a high pressure piping (chapter IX). The last interpretations of the code that I have, that confirm this contradictory situation comes from 2005 in the INTERPRETATIONS B31.3 VOL 20, inquire 20-09.
Does anyone know if the ASME B31.3 Committee for High Pressure Piping is reconsidering the situation, taking account the existence of Code Case 181-1 and the superior POD and sizing capabilities of TOFD-PA combinations or AUT against Gammagraphy, including the most critical cases as thick sections where gammagraphy shows extremely poor results?
Thank you to all friends!

16:20 Dec-10-2009
Larry Richardson
Re: UT in ASME B31.3 High Pressure Piping In Reply to Carlos Correia at 13:56 Dec-10-2009 (Opening).

HP Piping is handled by a separate committee from regular piping. CC 184 has been issued to deal with the UT situation regarding HP piping and to my understanding will be incorporated into the 2010 edition.

06:08 Dec-16-2009
Re: UT in ASME B31.3 High Pressure Piping In Reply to Carlos Correia at 13:56 Dec-10-2009 (Opening).

Code Case 181 allows this.
Reply: It is the opinion of the Committee that
alternative UT acceptance criteria as described in
this case may be applied in lieu of those described
in para. 344.6.2 of ASME B31.3 provided that all
of the following requirements are met:
(a) The ultrasonic examination area shall include
the volume of the weld, plus the lesser of 25 mm
(1in) or t on each side of the weld
(b) A documented examination strategy or scan
plan shall be provided showing transducer
placement, movement, and component coverage
that provides a standardized and repeatable
methodology for weld acceptance. The scan plan
shall also include ultrasonic beam angle used, beam
directions with respect to weld centerline, and pipe
volume examined for each weld. The
documentation shall be made available to the
owner’s Inspector.
(c) The ultrasonic examination shall be
performed in accordance with a written procedure
conforming to the requirements of Section V,
Article 4.1 The procedure shall have been
demonstrated to perform acceptably on a
qualification block(s). Qualification block(s) shall
be in accordance with Section V, Article 4, T-
434.1.2 through T-434.1.6. The qualification
block(s) shall be prepared by welding or the hot
isostatic process (HIP) and shall contain a
minimum of three flaws, oriented to simulate flaws
parallel to the production weld's fusion line as
(1) one surface flaw on the side of the block
representing the pipe OD surface
(2) one surface flaw on the side of the block
representing the pipe ID surface
(3) one subsurface flaw
(4) If the block can be flipped during UT
examination, then one flaw may represent both the
ID and OD surfaces. Thus only two flaws may be
Flaw size shall be no larger than the flaw in Table 1
or 2 for the thickness to be examined. Acceptable
performance is defined as response from the
maximum allowable flaw and other flaws of
interest demonstrated to exceed the reference level.
Alternatively, for techniques that do not use
amplitude recording levels, acceptable performance
is defined as demonstrating that all imaged flaws
with recorded lengths, including the maximum
allowable flaws, have an indicated length equal to
or greater than the actual length of the flaws in the
qualification block.
a/t ��
Surface flaw < 0.087 < 6.4 mm (0.25 in.)
Subsurface flaw < 0.143 < 6.4 mm (0.25 in.)
(a) t = the thickness of the weld excluding any allowable
reinforcement. For a buttweld joining two members having
different thickness at the weld, t is the thinner of these two
thicknesses. If a full penetration weld includes a fillet weld,
the thickness of the throat of the fillet weld shall be
included in t.
(b) A subsurface indication shall be considered as a surface
flaw if the separation (S in Fig. 1) of the indication from the
nearest surface of the component is equal to or less than
half the through dimension (2d in Fig. 1, sketch [b]) of the
subsurface indication.
(d) The ultrasonic examination shall be
performed using a device employing automatic
computer based data acquisition. The initial straight
beam material examination (T-472 of Section V,
Article 4) for reflectors that could interfere with the
angle beam examination shall be performed (1)
manually, (2) as part of a previous manufacturing
process, or (3) during the automatic UT
examination provided detection of these ref1ecctors
is demonstrated as described in Para. (c)

13:42 Dec-16-2009

Nigel Armstrong

Engineering, - Specialist services
United Kingdom,
Joined Oct 2000
Re: UT in ASME B31.3 High Pressure Piping In Reply to LG at 06:08 Dec-16-2009 .

Hello Lloyd

Carlos was correct in that B31.3 Interpretation 20-09 (issued October 2004) stated that whilst UT was allowed for normal, severe cyclic and Cat M fluid services it was specifically disallowed for Chapter IX HP piping. At the time of issue there was no mention of auto or semi-auto UT.

In January 2007 auto and semi-auto UT were allowed for all categories with the issue of Code Case B31 181-1. Manual UT could not meet the requirements of this CC, so manual was still not allowed for HP piping.

In October 2009, Code Case 184 was approved which nowhere discriminates between manual and computerised inspections for HP piping and with length-based acceptance criteria, as per radiography. A new para K344.6.3. "Welds", requires performance demonstration and procedure qualification. I expect Owners will decide which CC to cite depending on which acceptance criteria they wish to use.

The word "labyrinthine" springs to mind!

14:40 Jun-29-2013
Vishal Gupta
Re: UT in ASME B31.3 High Pressure Piping In Reply to Nigel Armstrong at 13:42 Dec-16-2009 .

As per CC-181, any defect indication above 20% reference level shall be investigated and evaluated. Does it mean defect indication greater that 6.4mm but echo height less than 80%(reference level) shall be repaired as no where in CC-181 it is mentioned that, only indication above reference level shall be repaired.

07:37 Jan-07-2016


NDT Inspector,
Joined Sep 2010
Re: UT in ASME B31.3 High Pressure Piping In Reply to Nigel Armstrong at 13:42 Dec-16-2009 .

Hi Nigel,

Excellent explanation regarding the case of High Pressure Pipe. Now, I am faced with the same case in which all the decisions depend on the owner.
Little bit unfair where we can sizing high of the flaw but should follow workmanship acceptance criteria.
As your said "labyrinthine" springs to mind!
By the way, a lot help your previous comment..

19:33 Jan-08-2016


Joined Jan 2010
Re: UT in ASME B31.3 High Pressure Piping In Reply to wilyan_safitra at 07:37 Jan-07-2016 .

Hello Wilyan

As I’m sure you know the information in this thread is now outdated. While I cannot find that CC 184 has been annulled, B31.3 now references direct to Section VIII KE-301 & KE-302 making 184 effectively obsolete.

With respect to CC-181, unless there is some interpretation I’m unaware of I don’t see how this code case would apply at all to B31.3 chapter XI. CC-181 is an alternative to the acceptance in 344.6.2 and would only apply to those categories that reference that acceptance. Chapter XI does not.

In short, workmanship is not allowed by anything I read. ASME Sec VIII KE-301 and KE-302 is clearly fracture mechanics

Hope this helps

13:16 Jan-07-2017

Erhan Turgut

Joined Jul 2016
Re: UT in ASME B31.3 High Pressure Piping In Reply to Nigel Armstrong at 13:42 Dec-16-2009 .

It is obvious since the CC 184 or B31.3-2010 edition (includes the CC w/o any change) that the ultrasonic examination shall be performed using a device employing automatic computer based data acquisition (referenced SEC VIII Div.3 KE-301)
But, because the Code is referencing KE-301 and KE-302 only for the test method (not the acceptance criteria), I agree that we have to apply the length and flaw type based acceptance criteria of Table K341.3.2, as per radiography. (Also CC 184 gives the same acceptance criteria, only editing some lines.)

My problem is, how to apply internal porosity criteria. Table addresses ASME Sec VIII Div.1 Article 4 , which is obviously only applicable to RT. If I try to apply this criteria to PAUT, it is weird isn't it ?
So, may we better use the same criteria for slags for also porosities ?
(Because it is already rejecting if a slag is exceeding the reference level regardless of length.
And if there is a cluster and cumulative length is exceeding 6 mm for example, it is rejected again even not exceeds the reference level, for thickness below 19 mm.)

Actually, now I am preparing a UT procedure on behalf of Engineering, so I am the one to decide that. But for sure it will be reviewed by the Owner. And we don't have time left, so I should give the best decision in order to get it accepted quickly.

Thank you in advance for helping

15:02 Jan-07-2017


United Arab Emirates (UAE),
Joined Dec 2016
Re: UT in ASME B31.3 High Pressure Piping In Reply to Erhan Turgut at 13:16 Jan-07-2017 .

Really a great supportive interaction face.We can solve the best issues by analysis the detailed ideal support from experienced experts.


© NDT.net - The Web's Largest Portal of Nondestructive Testing (NDT) ISSN 1435-4934

Open Access Database, |Conference Proceedings| |Articles| |News| |Exhibition| |Forum| |Professional Network|