RT1 or RT4

[wcw1985]

Dear forum member,

I have a pressure vessel, one of the circumference seam is considered as Type 3 joint as per table UW-12. (Because we can't inspect the internal quality of the weld)

If i do 100% radiography on all the joint, can the vessel be categorised as RT1?

Regards,
Wcw

 

[GenB]

Tp 3 because you welded from one side only. Even if fully RT does not qualify the vessel for RT1,

 

[Jano6924]

A Type 1 weld requires compliance with UW-35, and you shall inspect both faces (internal & external) of weld in its entire length. A radiograph on a Type 3 joint will not prove full pennetration nor total fusion and will not satisfy UW-35. Therefore the Type 3 seam will remain as Type 3 even if you make 100% radiograph on subject joint.

Regards.

 

[wcw1985]

Thanks for reply, Does that means RT1 require all the joint to be type(1)?[pre][/pre]

My query is not about to make type(3) joint into type (1), my query is that "can type (3) joint comply to RT1 requirement?".

 

[Jano6924]

As GenB stated, the vessel does not qualify for RT1 since you have a Type 3 joint.

Regards.

 

[david339933]

Use a backing strip instead (Type II), and you will have RT-1.

 

[GenB]

David33... I understand that Circ tp2 combined with shell full RT will only qualify for RT2, never RT1. It will allow E=1 though. GenBlr

 

[david339933]

Full Radiography done with Type II backing strip is RT-1. For full RT Cat. A and B shall be Type I or Type II. UW-11(a)(5))a)

 

[Jano6924]

Agreed with david33993, he is correct.

Regards.