Valve dimensions and pressure-temperature ratings are defined by which standard?

• A. ANSI/ASME B16.34
• B. ASME Section IV
• C. ASME Section V
• D. B16.9

Answer: (A)

Valve dimensions and how the allowable pressure changes with temperature are defined by a standard that provides the official rating tables and the dimensional data for valves. ANSI/ASME B16.34 is the standard that covers valve types, general design requirements, and the exact dimensions, end connections, and pressure–temperature ratings used in piping systems. It includes how the pressure rating varies as temperature rises, ensuring a valve selected for a given service won’t exceed its limits. The other standards touch on different topics: one focuses on boilers, another on nondestructive examination, and the last on fittings rather than valves, so they don’t define valve dimensions and ratings.