Understanding of Article 4.5.3.2.2(4) of the new capacity regulations?

In my opinion, clause 4.5.3.2.2(4) of the new code, which stipulates that for pressure vessels whose welding joint coefficient is set at 1.0, Class A and B joints require 100% RT inspection, is consistent with paragraph 6 of article 85 of the old code; this is because there is no issue of Class A or B welding joints in seamless-welded pressure vessels； So there’s no need to consider it ； However, when seamless pipes are used to make the vessel shells of equipment, and such pressure vessels are designed and manufactured in accordance with the standards set by the Ministry of Chemical Industry, the shells must undergo relevant re-inspections in line with those standards.

I think what the original poster said makes sense. If the equipment cylinder is made of seamless steel pipes, and the requirements for the equipment are not very stringent, then radiographic inspection only requires partial testing; however, according to regulatory standards, 100% inspection is necessary. I don’t think it’s appropriate

I think the new regulatory requirements are sound; the weld coefficient refers to the coefficient of the longitudinal welds on the shell, and the joints between the shell and the head do not need to be inspected 100%.

The welding joint coefficient for pressure vessels made of welded tubes is not determined based on those made of seamless tubes

The weld joint factor refers to the longitudinal weld; it does not exist in seamless steel pipes. What’s wrong with that?

This post was last edited by DHsj0033 on 2009-11-25 at 10:37. Original poster Haiyou: One should note the condition in the specifications regarding the inability to conduct internal inspections. Generally, seamless pipes are used only for those with a nominal diameter of 400 or less. In cases where there is a detachable flange structure, and no Type A or Type B welds are present on the sides, it becomes impossible to carry out internal inspections. As a fallback option, internal inspections can be carried out, which indicates that the nominal diameter of the pipe is large enough to allow for the installation of inspection holes. If the weld coefficient is set at 0.1, what’s the problem with performing 100% flaw detection in cases where there are Type A and Type B welds? I don’t quite agree; there is no such thing as Class A or Class B welds for seamless pipes. Isn’t the circumferential weld connection between a seamless pipe and a head considered Class B?

Take a good look at what point 4.5.3.2.2(4) says