B31.3 vs. B31.1

[sabre61]

The majority of our piping is per B31.3 but on one particular job it is specified as B31.1. The customer specification also calls for 5% radiography on the butt welds per B31.1. After reviewing B31.1 it does not appear to specify a % of welds to x-ray if you meet the criteria specified in Table 1 so I assume it is all of the welds meeting this criteria. The design conditions of this particular job would not require any x-ray in themselves other than the addittional 5% requirement of the customer specification. The problem is what to do if an x-ray is deemed unacceptable. B31.3 requires 2 additional x-rays for the rejected one where as B31.1 does not appear to require this (I assume this because the code itself would already require all of the welds x-rayed if you where x-raying based on only the code). I would assume that the rejected weld needs to be repaired and shot again but do not see any requirement for additional shots. Not being familiar with B31.1 I was wondering if anyone had any experience with this type of an issue.

Thanks

 

[Lynx]

B31.3 Para.341.4 shows examples of NDE using radiography.
Chapter VI in B31.3 will list all inspections but B31.3 will not tell you to what extent you must use as a % of NDE.
ASME B31.3 is a standard to follow. Most companies require you to follow B31.3 as a minimum requirement.
If you have shot a weld an it has tested bad the general rule is to repair the weld, then shoot the next three welds the welder makes.

 

[Lynx]

B31.3 Para. 341.4.1 (1) does say at least 5% of fabrication must be tested with radiography. Some clients may require 10%. It all depends on what the service is. Catagory D may not require any testing other than visual & service test.