How to prepare product welding test plates for the takeover and cylinder?

No, what the original poster is referring to is the \"evaluation of tube-sheet type specimens.\" The correct approach is as follows: For specific structural types, one can refer to the explanations in standard JB4708-2000, Chapter 10, which deals with the evaluation methods for type specimens, and Figure 17. It should be emphasized here that single-sided welding, or single-sided welding with double-sided formation, must be used. The main purpose of this evaluation is to prove that the company’s welding processes and techniques are capable of achieving full penetration. This post was last edited by yaoyongyoyo on 2009-3-17 at 11:17

For the welding of the take over to the cylinder, full penetration is generally required, and there is a significant difference between full penetration and single-sided welding with double-sided formation! The requirements for single-sided welding with double-sided formation are even stricter! It’s not easy to achieve in actual welding either! It’s just my personal opinion; please correct me if I’m wrong!

For how to prepare welding test plates, refer to GB150 and the Pressure Vessel Code

In the pressure vessel manufacturing industry, when joining nozzles to cylinders, a full-penetration test specimen is required as part of the process evaluation, in order to demonstrate that the company has the capability – both in terms of welding procedures and the skills of the welders – to achieve full penetration. There are two types of full penetration: double-sided welding and single-sided welding. When welding products, some nozzles and cylinders can be welded using double-sided welding, while others cannot. If you use a double-sided welding full-penetration tube-sheet test specimen, it only proves that full penetration can be achieved through double-sided welding; it does not indicate that full penetration is possible with single-sided welding. This is because welding a test specimen for full penetration using single-sided welding is more difficult than doing so with double-sided welding, as you yourself acknowledge. Therefore, I believe that it is better to conduct the process evaluation using single-sided welding, as this provides a better indication of the company’s ability to achieve full penetration

When conducting process evaluations, it is essential to take into account potential problems, such as full penetration welding on only one side as mentioned above. For many products, the nozzles and cylinders cannot be welded on both sides; therefore, welding on just one side is necessary. It is best to carry out evaluations for single-sided welding during process evaluations, as this provides greater versatility and demonstrates a stronger ability to achieve full penetration

When conducting weld procedure qualification for the welding of the nozzle to the cylinder, single-sided welding should be chosen first, as it is more difficult to achieve full penetration with single-sided welding compared to double-sided welding

Welding test plates and welding procedure qualification are not the same thing, right? If it is specified in the drawings, a welding test plate should be used ； I’ve never encountered situations where test plates were required for the welding of nozzles and cylinders; if there’s process evaluation support available in this case, then that should be sufficient… Why would test plates still be needed? Crayon’s perspective: Seeking an authoritative explanation for Xiao Cai Xue* Part 2……

It is estimated that the requirements of the design specifications are being followed; at this point, it is sufficient to create a simulated specimen. Of course, this simulated specimen should be analyzed in accordance with relevant regulations, and tests such as gold plating inspection should also be carried out!

If the drawings require a welding test plate, you can simply make one using the same welding process as that used for your product.