ASTM A333 Heavy Wall Pipe Limitations

[Morts81]

The scope of ASTM A333/A333M specifically states "Some product sizes may not be available under this specification because heavier wall thicknesses have an adverse effect on impact properties."

We currently have an issue where we have identified longitudinal cracks in DN300 47mm thick A333 Gr6 seamless piping. Our Quality Department are carrying out all the relevant inspections, etc, however, in parallel I'm trying to understand what heavy wall limitations exist for this material grade. I've spent time searching the net for papers, etc but nothing has come up as yet.

Does anyone have experience with (or reference to) D/t limitations for ASTM A333 Gr6?

Thanks in advance.

 

[AGazo]

pls review ANSI Pipe Schedule for D/t.

 

[SJones]

The achievement of the required pipe properties will be dependent upon a number of manufacturing variables and manufacturing equipment performance. Thus, the limitations have a tendency to be pipe mill specific and it will be difficult to define an absolute threshold. Try reviewing the notional dimensional supply limits of several manufacturers to build a picture of what the limiting dimensions may be.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[GD2]

Morts81,
Tell us something more about the application and the code of construction. A333 gr 6 pipes are widely used in refinery services. Design thickness equation in ASME B31.3 limits WT to t<D/6. In our case,47 mm WT is below the 54 mm limit for DN 300 pipe but with a 12.5% positive mill tolerance it will hit the max limit. Higher WT is no good for notch toughness. It also increases the MDMT
Throw some light on the service fluid, Design conditions and most importantly the MDMT. A333 gr 6 pipes uses are limited to -45C.
In the meantime, we will await to hear the Quality depts finding.

GDD
Canada