impact test of A106 Gr B

[smart143]

i am using A106 Gr B pipe of 16" sch 160 & MDMT is - 20 deg C.
Not sure impact test is required per 31.3 code.
If yes then shall i chose a Weld procedure where HAZ & weld are impact tested to atleast MDMT?
Again for above my base metal thickness limit will be T/2 to T+6 mm & not as per
QW 403.6 of SEC IX?

 

[Duwe6]

SA-106 is like most other ASME materials, and has an MDMT of -20°F // -29°C. You are fine.

If you do qualify a 'cold' WPS, try using -40°C. It is easy to get charpys to pass, and there are few places on the planet that ever get colder than this.

 

[SJones]

has an MDMT of -29deg C. You are fine

Only up to 12.5 mm nominal thickness. A106 is a curve B material in Figure 323.2.2A.

try using -40 deg C. It is easy to get Charpys to pass

If only it were that simple. A106 is not a steel design for low temperature and it would be more a case of 'you would be fortunate to get Charpys to pass'.

Steve Jones
Materials & Corrosion Engineer

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

 

[smart143]

Thanks jones.
That means impact is really required. What about base metal thickness limit as now impact is required?

 

[SJones]

For -20 deg C, with a curve B material, you can have up to a 15 mm nominal thickness before invoking the requirements of Table 323.2.2.

Steve Jones
Materials & Corrosion Engineer

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

 

[smart143]

thanks Jones.
But i am more keen on limit of base metal thickness for weld procedure .Will it be as per QW 403.6 of Sec IX or T/2 to T+6 mm of 31.3 as i see i will have to weld fairly large cupon for qualifìcation.

 

[stanweld]

For piping systems subject to B31.3, the thickness limitations of B31.3 apply.