D1.1 PT and MT Acceptance Criteria

By DGXL

Date 04-02-2005 17:37

MBSims:
Table 6.1 is used for PT/MT (6.14.4./6.14.5). Same loop.

By MBSims

Date 04-02-2005 17:52

I guess I should read the words in 6.10 instead of just looking at them!

"Welds that are subject to MT and PT, in addition to
visual inspection, shall be evaluated on the basis of the
applicable requirements for visual inspection."

I guess this get you back to Table 6.1, although it doesn't seem appropriate for PT. If you use the VT porosity criteria to evaulate PT bleed-out, the acceptable porosity diameter is much smaller for PT than VT.

I think this may also be an editorial problem that goes back to the edition when the new format was introduced. The words "whichever is applicable" make no sense in the current edition. The words "Section 6, Part C" previously referred to paragraphs in sections 8, 9 and 10 and "whichever is applicable" made sense there.

By - Date 04-04-2005 16:57

Mr. Sims,
The "whichever is applicable" statement refers to either 6.14.4 or 6.14.5, meaning either MT or PT.

I agree with you that the VT criteria are not readily applied to MT or PT. Some of the criteria from Table 6.1 are clearly related only to VT (profile; undersized welds; etc.). If you try and boil it down to look like a set of acceptance criteria "designed" specifically for MT or PT (such as ASME Sec VIII), you will get something like
- no linear indications allowed (D1.1 requires no cracks and thorough fusion) though some might debate that you can allow linears based on the allowable undercut
- rounded indications allowed as per the porosity limits of Table 6.1 (8)

Mankenberg

By MBSims

Date 04-08-2005 03:21

That's kinda what I got from Table 6.1 also. I don't understand why they can't be more straightforward and provide the acceptance criteria in a less confusing form. Just another reason why D1.1 is so user UN-friendly.

By jfwi

Date 04-08-2005 22:27

The acceptance criteria should be spelled out in your written procedure. D1.1 mentions SNT-TC-1A the recommended practice published by ASNT, which will cover training, and the acceptance criteria will be applicable for the needs of their product.

Jerry

By MBSims

Date 04-08-2005 23:04

I agree, it should be in the procedure. But I was asking what D1.1 requires, not what someone's procedure requires.

By bmaas1

Date 04-09-2005 13:31

The acceptance criteria shall be in conformance with Section 6 part C of D1.1.

Read 6.14.4 and 6.14.5 page 204 of the 04' edition.
Basically it is the visual acceptance criteria for these two methods.

Brian

By jfwi

Date 04-12-2005 16:41

I must say after reading my own posting that it do not say much for which I apologize. Section 6 part C 6.10 starts a revolving circle from what I can read. 6.10 "Testing shall be performed in conformance with 6.14.4 or 6.14.5 which ever is applicable." 6.14.4 & 6.14.5 last part of the paragraph "... the standard of acceptance shall be in conformance with Section 6, Part C, whichever is applicable.” is at the end of each paragraph. The reference to ASTM E709 for MT and ASTM E165 is where we will find the acceptance criteria. I have read both and now remember that my written procedure includes these as reference material. Hope that might be a better answer than my last posting.

After a little more research try ASTM E1444 for MT criteria

Jerry

By - Date 04-14-2005 15:57

Jerry,
I definitely agree with you that the statement "...whichever is applicable" at both 6.14.4 and 6.14.5 is confusing and unnecessary. That statement should be removed from both of those paragraphs, and if you read it that way, it becomes clearer.

In fact, if you look at ASTM E709, ASTM E165, and ASTM E1444, they all provide only technique requirements/practices for MT or PT. They do not provide acceptance criteria. They all refer you to use the governing standard for acceptance criteria (for instance in E1444 this is stated in paragraph5.1). In the case of the governing standard AWS D1.1, the acceptance criteria are found in Section 6, Part C.

As stated in my previous post, and indeed as stated in D1.1 paragraph 6.10 ("welds that are subject to MT and PT, in addition to visual inspection, shall be evaluated on the basis of the applicable requirements for visual inspection"), the MT and PT criteria in D1.1 are not written specifically as MT and PT acceptance criteria, as you will find in many other codes that refer to linear and rounded indications. In D1.1, the "applicable" VT criteria are to be used. Some of the VT criteria are not applicable to MT or PT, such as weld profile, weld size, etc.

Mankenberg