Evaluation method for pressure vessel manufacturing codes: the influence of ASME unit conversion

This paper presents an assessment of the selection of manufacturing codes for pressure vessels. We focus on one of the most relevant approximation methods used in manufacturing calculations for pressure vessels, i.e., the unit conversions of the ASME boiler and pressure vessels (B&PV) code. To evaluate the influence of its conversions, several errors arising from the manufacturing process and measurement systems have been calculated, estimated and considered. In addition, a decision tool for manufacturing codes of pressure vessels with novel considerations based on stringency levels is presented to improve the current selection process. The general conclusion is that adjusting the pressure units is not recommendable when designing a pressure vessel due to large errors that can accumulate. Furthermore, the length conversion is only suitable for parts manufactured with maximum dimensions of five inches (125 mm).