a standard practice for Instrument Valves published by the Manufacturers Standardization Society (MSS)
The most recent update, MSS SP-99-2023, is available for purchase in PDF and book format from the Manufacturers Standardization Society (MSS) and authorized distributors like the ANSI Webstore. Scope and Technical Specifications mss sp99 pdf
This section is crucial for Quality Assurance (QA/QC). It defines the required tests: a standard practice for Instrument Valves published by
This is the most referenced section. It contains tables showing the maximum allowable working pressure (MAWP) at various temperatures. For example, a 316 stainless steel needle valve might be rated for 3000 psi at 100°F but only 2000 psi at 600°F. mss sp99 pdf