How ASME B16.5 pressure classes really work: why Class 300 is not 300 psi, how ratings fall with temperature by material group, ASME-to-PN crossover, RF/FF/RTJ sealing faces, and the five flange selection mistakes that cause plant leaks.
A buyer’s guide to forged fittings and flanges: B16.11 socket-weld and threaded classes 2000-9000 and their pipe schedule pairing, B16.9 versus B16.11, flange types WN/SO/SW/THD/LJ/BLD, RF/FF/RTJ faces, materials, and the ordering checklist that prevents substitution.
Certified bearing and tool steel buying: GCr15/100Cr6 oxygen and inclusion requirements, spheroidized delivery, cold-work/hot-work/plastic-mould tool steel families (D2, H13, P20), ESR quality, and the specification fields that separate real grades from labels.
Forged versus cast steel for buyers: what forging does to grain structure, toughness and fatigue life; where casting wins on shape; the ASTM/EN grade map; NDE expectations; and the specification wording that prevents silent substitution.