Non-destructive testing proportion issue

You mean to use the necked butt-welded flange as a equipment flange, right? I think it’s sufficient according to the equipment’s non-destructive testing requirements.

Bro, take another look at 10.8.2.1~10.8.2.3 – the statement that \"all weld joints formed by the butt jointing of fittings with a diameter of 250 mm or more and long-neck flanges must undergo radiographic inspection\" is incorrect; a radiographic inspection rate of >=20% is sufficient.

Bro, taking another look shows that what you said is wrong. Additionally, if the equipment flange is a butt-welded flange, 100% flaw detection is required for the butt welding to the shell, provided that the requirements specified in the container flange standards are met.

Clause 10.8.2.2(e) of GB150-1998 stipulates that all weld joints formed by the butt jointing of nozzles with a nominal diameter of 250 mm or more and long-neck flanges shall be subject to radiographic inspection. My understanding of this provision is that although it is 100%, it still falls under the category of partial testing as specified in GB15010.8.2.2; it’s just that the entire weld is inspected in this case. The acceptance standard is the same as that for the equipment itself. Butt weld between the flange of the welded-necked container and the shell: When the operating pressure of the equipment is 80% or greater of the maximum allowable operating pressure of the equipment’s flange, 100% radiographic inspection is required; a grade II result is considered acceptable. If this condition is not met, then the same inspection procedures as for the equipment apply.

I agree with you; it’s a shame I can’t give you extra points:handshake

Except as specified in 10.8.2.1 where 100% testing is permitted, the weld joints formed by the butt jointing of nozzles with a diameter of 250 mm or more and long-neck flanges may be subject to local radiographic testing or ultrasonic testing at a rate of not less than 20%"

Is there any basis for saying that? Following the regulations in GB150 won’t work, I think the rules in GB150 are unreasonable

I also think it’s wrong, but since the standards are set that way, what can be done to overturn them?

I agree with the first part of the view; what is the basis for the second part? It doesn’t conform to the standard regulations, right?

The equipment flanges shall be inspected in accordance with the circumferential welds of the equipment, and the inspection ratio shall be determined based on the drawing requirements and standards. It cannot be considered as taking over

The latter half of the 5th floor is in accordance with the provisions of JB/T4703-2000.

The standards are clear: it is a takeover process, and since the equipment flange is connected to the housing, it should be handled in accordance with the drawing requirements, just like the equipment’s ring welds

The statement on the 5th floor is correct. To understand the standards, one must consider the relevant clauses in context and grasp the editor’s original intent.

Regarding whether 100% radiographic inspection should be carried out on the butt welds between the flanges and the shell of welded containers with necks, refer to JB4700 – Technical Requirements for Container Flanges, which contains detailed specifications

Is there a difference between necked butt-weld flanges and long-neck flanges?