John,
I was thinking of an interpretation request such as this:
"May piping components with an undertolerance of not more than the smaller value of 0.01 in. or 6% of the required design thickness be used at the full design pressure for the specified design thickness?"
This borrows heavily off...
Normally this would not make a difference. However, sometimes we make machined tube to tube adapters where one end could be .875 OD X .049 wall and then it does make a difference. 6% of the wall thickness in this case is only .0029. With OD/ID machining tolerances and concentricity issues...
Normally the machined tubular parts we use have +/- .003" on all dimensions. To calculate MAWP per B31.3, B31.1, etc. we use the minimum material (wall thickness) condition, given the machining tolerances. Although it is not really relevant to the discussion, UG-16 of Section VIII allows the...
We are attempting to weld small tubular sections (7/8" OD x 1/2" ID) of aged Inconel 718 with 625 filler. We're using 625 filler for two main reasons; 1. Availability vs. 718 or 725 filler 2. Lower tendency for weld cracking (we are told) compared to 718/725. We need the strength of 718 in one...
We have never done a Sec. IX hot-wire GTAW WPS before, that's why I'm asking. Since the WPS's will have impact testing, I'm assuming that the hot-wire heat input contribution must be accounted for, no?
Since impact testing is not possible on such a small coupon, the WPS, per Section IX would actually be qualified from .0625 to 0.196. My point is, that since within this range there IS a thickness that a 2.5mm specimen could be machined from (let's say you need 1/8" thk. for purposes of...
Per B31.3, impact testing for a weld is not required if the maximum obtainable width across the notch is less than .098".(correct me if I'm wrong) Base materials and filler metal are good at the -50F temp. If I run a .096" thick PQR, naturally I cannot get a charpy of .098" width. This would...
The hardness values are meant to meet MR0175 and API 6A requirements to prevent stress corrosion cracking, as you mentioned. As such, it is very important not to exceed maximum values.
Currently ASME IX requires supplementary essential variables (SEV) only when impact testing is required, I believe. Many of the GTAW WPS we have (for butt and fillet welds, not hard-facing) require HAZ, base metal, weldment hardness testing. Do you think it is a good practice for these types...
