How many sets of test plates should be prepared for different welding methods?
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According to the pressure vessel codes and GB150-98, weld test plates should be prepared for the longitudinal welding of cylinder sections. If submerged arc automatic welding is used for longer cylinder sections while manual arc welding is used for shorter ones, how many sets of test plates are required? Please provide the basis for this approach.
Product welding test plates should be prepared separately for different welding processes. The basis is Article 5, Sections 4(1) and (2) of the Code. The details are as follows: 1. The material of the product’s welding test plates, as well as the welding and heat treatment processes, must fall within the acceptable range determined by the welding procedure qualification for the welded joints of the pressure components they represent ； 2 When the coverage of the weld procedure qualification for different longitudinal weld joints on a pressure vessel’s shells (including those on the head, tube sheet, and cylinder) varies, test plates shall be welded separately for each corresponding longitudinal weld joint, using the appropriate weld procedures.
There is a small device with two flat end caps (of different thicknesses) made from two different materials. Due to manufacturing requirements, two different welding methods must be used, and according to the regulations, 5 sets of test plates are required – which is absolutely excessive. It’s not economical to manufacture the device in accordance with these requirements; these regulatory specifications are rather unreasonable. In fact, the evaluation of welding processes also relies on test plates
It is necessary to produce test plates as required; if this is to be avoided, consideration should be given during design and manufacturing to using the same material and the same manufacturing process. If the quantity is large, it may be possible to process batches instead of individual units
If it’s the same plate thickness, make two pieces – one for each welding method.
After reviewing the draft of the new specifications, I realized the irrationality of using test plates; considering the elimination of such product welding test plates is indeed a good thing for companies. As mentioned by the original poster, as long as the tests fall within the scope of the same process evaluation, only one test plate is needed; otherwise, more plates will have to be used. The exact number of plates required depends on the coverage provided by the welding process evaluation
For different welding processes, welding test plates should be prepared to conduct welding process evaluation
The argument for the fourth floor is persuasive; there are far fewer problems