Which pressure vessel RT marking designation indicates a joint efficiency of 0.85?

The marking designation that indicates a joint efficiency of 0.85 in pressure vessel regulations is RT-3. In the context of ASME (American Society of Mechanical Engineers) standards, these markings are associated with the results of radiographic testing (RT) of welds.

A joint efficiency of 0.85 suggests that the welded joint is considered to be of higher quality and safety compared to those with lower joint efficiency values. This allows for a corresponding increase in the allowable stress that can be used in the design calculations of the pressure vessel, making RT-3 appropriate for applications where a reliable welded joint is critical.

Understanding the implications of joint efficiency in pressure vessel design is essential for ensuring safety and reliability. Different RT designations reflect varying levels of quality assurance and testing adequacy; for example, higher efficiencies offer greater confidence in the integrity of the vessel under pressure.