Preparation of product welding test plates: Can the head test plates and the cylinder test plates be combined?
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It meets the requirements of the head standard GB/T25198 (e.g., for containing highly hazardous media) – it is necessary to prepare welding test plates for the heads (since the heads are joined together); is it also required to prepare welding test plates for seam A of the cylinder? (The thickness of the cylinder and the head is the same.) If the cylinder does not require heat treatment while the head does-----is it necessary to prepare test plates separately in such a case?
This post was last edited by ruoshmm_2009 on 2025-8-28 07:34. It’s my personal opinion – they cannot be combined, as these two belong to different standards. For stress-relief heat treatment, no test specimen is required; however, standard requirements for recovery-property heat treatment specify the use of a test specimen. Moreover, 25198 seems to relate to the impact of different welding methods on the head test plates (for example, the closing welds and joint welds on conical heads are not necessarily welded using the same method). ) No such requirement was made either; it is recommended to refer to the relevant provisions for 150 and increase the number of end plate test pieces. Welcome to discuss together.
It shouldn’t be possible to merge them! The purpose of GB/T25198 for preparing welding specimens is likely to simulate heads with seams; during the forming process, the welds are subjected to mechanical stresses resulting from heating and pressing (in fact, the specimens themselves are not subjected to pressing). Moreover, for either non-alloy or alloy steel heads, heating-based forming is essentially equivalent to normalizing, and if heat treatment is required for the equipment, it is stress-relief treatment (tempering), with different temperatures involved.
A prerequisite for merging is that the welding processes for the head and shell welds are identical.
Furthermore, the welding of the head joint must be carried out by the container manufacturer itself.
They should not be combined; the thermal processing procedures for the test plates of the cylinder’s longitudinal seams and those of the head are generally different, as are the welding qualification standards used, so they cannot be combined
I just realized that my understanding was incorrect; there is a corrigendum for 25198 regarding these requirements: Paragraph 2 should be added to 6.9.3, stating that \"For head welding specimens, heads with the same material standard, the same material grade, the same thickness, and those that are welded using the same welding procedure and subjected to the same heat treatment can have their welding specimens prepared in batches.\" ”
Regarding the corrections in GB/T25198-2023, does it mean that for the welded end caps of one or a batch of equipment, they \"can be processed in batches…\"? In other words, several end caps that meet the same criteria can be combined to form one test specimen, regardless of the cylinder?
I believe that the joint between the head and the cylinder can be formed by the equipment manufacturer using the same welding method and the same welding materials; a test plate can be used for this purpose
It is inevitable to prepare welding test pieces for end caps; end caps that have the same material standards, the same material grade, the same thickness, and are manufactured using the same welding procedures as well as undergoing heat treatment in the same furnace can serve as representative welding test pieces for the equipment. There is such a possibility.