The flange classes were originally called pounds. Class 300 flanges were called 300-pound flanges, and so forth. This was because, originally, Class 300 flanges were rated for 300 pounds per square inch (psi) pressure at a benchmark temperature. Pound (lb) meant psi, and had nothing to do with...
In accordance with ASME B31.3, does the phrase “maximum metal temperature...for the thermal cycle under analysis” in para. 319.3.1(a) require the use the normal upper temperature under operating conditions, and exclude all short-time excursions above such normal operating temperature in...
