253MA Seamless Tubes Manufacturer in Thailand

The product standard is ASTM A213, titled Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes, and ASME SA-213 is the related specification named for code work. S30815 is one of the austenitic steels its tables accept, and the grade column against that number is empty: a footnote there explains that the UNS number on its own identifies the alloy, which is why an order for seamless stainless steel 253MA tube names ASTM A213 and UNS S30815 and no TP prefix at all. A requisition that sizes a hot gas header in nominal bore and schedule is quoted instead as 253MA seamless pipes.

No 253MA stainless steel seamless tube leaves the mill unproved: each one takes either the nondestructive electric test or the hydrostatic test, and the selection stays with us where the order is not specific. A product analysis follows every heat, run on a billet or on a finished length. Lot work brings tension specimens, one tube for lots up to fifty and two for larger lots, plus a hardness reading from two tubes that A213 waives below 1.65 mm of wall. All of that is reported on the EN 10204 3.1 (3.2 on request) certificate, and the file behind it holds the raw material certificate, PMI on every tube, the heat treatment chart and the record of measured size and surface roughness. A third-party inspector is welcome to witness the testing, and an independent laboratory report can be issued, either one on request.

One finished tube per lot gives up the flattening specimens, at least 60 mm long, one taken at either end of it. Each specimen goes down cold between parallel plates in two stages. The opening stage tests ductility: no crack or break may show before the plates close to a height H, where H = (1 + e) t / (e + t / D), e taken as 0.09 for an austenitic steel, t the ordered wall and D the outside diameter. The closing stage tests soundness and carries on until the specimen parts or its opposite walls touch, and laminated or unsound metal revealed at any point in the test rejects the lot.

Flaring is proved on a different tube again, drawn from the same lot, with a specimen off either end of it. The two forming tests never run on one length, so an SS 253MA seamless tube lot reaches you with both results recorded.

A213 is just as plain about what the finished product must survive in the fabrication shop. Anything rolled into a boiler or into a tube sheet is required to expand and to bead with neither a crack nor a flaw appearing afterwards, while a superheater length has to stand up to the bending, welding and forging its own duty asks of it. The lot tests above are the evidence that it will, which is why they run on every lot and not on request.