【Weekly Topic】Issues regarding the fabrication of test plates for coal-fired steam boilers? (04.22~04.29)
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This post was last edited by salesment on 2011-4-20 at 17:54. Does anyone know how many test plates are required for the manufacturing of coal-fired steam boilers, including those for re-inspection and welding? The specific dimensions of the test plate, please
1) Products of the same steel grade, using the same welding process and under the same heat treatment specifications should be grouped together for continuous production (with no interruptions in production lasting more than half a year); each batch shall contain no more than 10 units. The manufacturing unit shall select one unit from each batch to use as a welding test piece； (2) For pressure vessels with a design pressure not exceeding 1.6 Mpa and made of materials from the Q235 series, 20R, or 16MnR, products of the same steel grade should be grouped together; one product per batch shall be selected for manufacturing a welding test plate on a regular basis each year ； (3) Glass-lined equipment does not require the welding of low-carbon steel plates (except when special requirements are specified). If production is interrupted for more than an hour past midnight, one unit of the product should be selected to create a welding test plate ； (4) For mobile pressure vessels manufactured in batches based on nearly identical design drawings, when produced manually in succession (with production interruptions not exceeding one year), no more than 10 units per batch shall be selected by the same manufacturing unit to be used for producing welding test plates. Welding test plates are produced in batches rather than one by one. If one of these test plates fails the tests, an additional number of test plates must be made for retesting and metallographic examination. If they still fail, the process must revert to producing welding test plates individually, until 30 test plates made from the same steel grade, using the same welding process and heat treatment specifications all yield satisfactory test results.
Strictly speaking, it is necessary to determine which mechanical property tests should be conducted based on the steam pressure, in accordance with the relevant standards. Then, add 60 mm for rejection and retesting based on the dimensions of the test specimen. Calculate the dimensions of the test plate. Generally, for test plates with a thickness of 20 mm, two plates measuring 1000x150 each are sufficient.
No explicit table available; calculation is required