Regarding the issue of using welding test plates in batches rather than individually per specification

Replacing individual units with batches means using products manufactured according to the same design specifications; it’s not about using the same welding method or producing in batches based on the same design. Stable welding quality can be demonstrated, and thus individual units can be replaced by batches

Sure. Because it meets the tolerance criteria: 1) materials of the same grade; 2) the same welding process (the important welding factors and additional important factors are within the acceptable range). Both 1 and 3, as well as 2 and 3, involve some common welding processes, so these can be combined; 3) the total number after combining exceeds 30 units. If the conditions are met, and with the approval of the technical supervisor of the manufacturing unit, it is possible to process the approval on a batch basis instead of per unit.

So, if in the future welding methods SAW and SMAW are used, with welding materials such as H10MnSi 4.0, HJ431, J507, 3.2, and 4.0, for products within the same range of 6–12 mm covered by those two process evaluations, into which batch group should the test plates be classified? Can it be divided into two batches either way?

Use SAW+SMAW products in batches instead of individually

According to the standards, \"when the same product uses materials of different grades, or is evaluated using different welding processes, or follows different heat treatment specifications, it can be treated as two separate products.\" I believe that by treating it as two products, it refers to cases where there are two (or more) welding test pieces, rather than using two (or more) different welding methods on the same test piece. When different material grades are used, it may be necessary to prepare two test pieces; the same holds true when different welding processes are used for evaluation. Following this logic, such cases can indeed be treated as two products. If a product has only one test piece, and the welding process used for evaluating that piece differs due to variations in the welding methods applied internally and externally, then the combinations of welding process evaluations for these two methods constitute one combined evaluation, and it cannot be treated as two separate products. If our company conducts a combined evaluation using SAW and SMAW methods, it should be treated as one single product. Therefore, in my opinion, such cumulative calculations should not be applied; cases where two different welding methods are used on the same test piece should be considered as a separate set of tests. This post was last edited by yaoyongyoyo on 2009-3-12 15:23]

Under the condition of using one test piece to represent a batch, I believe that it is the same welding process, and the welding quality has been proven to be stable through practical testing

The issue mentioned by the original poster is not the same; when two or more welding methods are used for the same weld, it is possible to conduct evaluations separately for each welding method or process, or to carry out a combined evaluation. If the combined evaluation is successful, one or several of these welding methods can be adopted to determine the effective range for each method in terms of its applicability to the welded component. For the same tank, such as a glass-lined jacketed container, since different welding procedures are used for the inner cylinder and the jacket – the inner cylinder requires a heat treatment process above its upper transformation temperature – this tank can be treated as two separate units: the inner cylinder as one unit (subject to heat treatment), and the jacket as another unit

In short, as long as the welding process qualification used is the same, it is possible to accumulate and treat them as batches rather than individual units

So can 1 and 3, as well as 2 and 3, be calculated cumulatively? According to you, does that mean that if the process evaluations are different, cumulative calculation isn’t possible?

The last edit to this post was made by prt0683 on 2009-8-4 at 21:58. You are referring to a situation where a single product has two test pieces with different process evaluations (different welding methods or heat treatment processes). What I mean is that if a product has only one test piece, and that piece was welded using two different welding methods, then two process evaluations must be used; in such a case, it cannot be treated as two separate products

It can be accumulated; if the welding evaluations are the same, that is, under the condition stated in Article 3 on page 38 of the regulations, 30 consecutive units can be treated as one batch

So, if in the future welding methods SAW and SMAW are used, with welding materials such as H10MnSi 4.0, HJ431, J507, 3.2, and 4.0, for products within the same range of 6–12 mm covered by those two process evaluations, into which batch group should the test plates be classified? Can it be divided into two batches either way?

The regulations regarding tolerance limits are difficult to understand. Does anyone have any information or explanations on this topic that they could share?

I believe that grouping should be done based on the welding method, and then considering factors such as the coverage area and other important or supplementary elements. Welding methods that are different from each other should not be grouped together; those that belong to the same welding method should be grouped separately, and it is not acceptable to accumulate quantities using just one welding method