Impact Testing 1

[Marc Stevenson]

1) I am aware of the impact testing exemption clauses in ASME SEC 8 Div. 1, but how do you decide if impact testing is required or not?
2) Some specifications demands 100% RT for all butt weld joints if the equipment contain any component that requires impact testing, where can I find this RT requirement in the ASME Code?

 

[metengr]

1) I am aware of the impact testing exemption clauses in ASME SEC 8 Div. 1, but how do you decide if impact testing is required or not?

Impact testing is based on material of construction, thickness and minimum design metal temperature.

2) Some specifications demands 100% RT for all butt weld joints if the equipment contain any component that requires impact testing, where can I find this RT requirement in the ASME Code?

This is not in the Code. Specifications are separate from Code and can contain requirements above and beyond the minimum requirements in the code of construction.

 

[Marc Stevenson]

@metengr Thank you for replying. Where can I find the RT requirements in the code for butt weld joints (if the equipment contains components which require impact testing)?

 

[metengr]

For Section VIII, Div 1 vessels, look at UW-11.

 

[Marc Stevenson]

Metengr, there are two clauses:-

Under Full RT: "(-b) Category B or C butt welds [but not including those in nozzles and communicating chambers except as required in (4) above] which intersect the Category A butt welds in the shell or heads of vessels or connect seamless vessel shell or heads shall, as a minimum, meet the requirements for spot radiography in accordance with UW-52. Spot radiographs required by this paragraph shall not be used to satisfy the spot radiography rules as applied to any other weld increment."

and Under Joint Efficiencies: "E = 0.85 when the spot radiography requirements of UW-11(a)(5)(-b) are not met, or when the Category A or B welds connecting seamless vessel sections or heads are Type No. 3, 4, 5, 6, or 8 of Table UW-12."

The exchanger's shell is an SA 333 Gr. 6 seamless pipe with 9.53 mm (0.375") with E= 0.85. I can't figure out if RT should be spot wise or 100%. The welding method is not known. The weld is butt-weld joints.

 

[david339933]

There is no requirement for RT because components must be impact tested in Sec. VIII-1.

 

[weldtek]

For P1 materials RT requirements are a function of design. One can determine RT requirements per Code by reviewing the vessel calculations. Review UW 11, Table UW 12 and the calcs.

 

[r6155]

For low temperature always I specify one spot in each butt weld when RT is not required by code.

Regards
r6155