Covers small valves and manifold valves designed for instrument, control, and sampling systems.
For those who have finally obtained the , here are the sections you will read most often.
Using instrument valves that do not comply with MSS SP-99 introduces severe risks to industrial facilities.
Ensures that valves from different manufacturers possess consistent end-to-end dimensions and connection styles (NPT, compression fittings, or socket weld).
Unlike standard industrial valves, instrument valves (such as needle valves, ball valves, and manifold valves) are designed for smaller bore applications, often for pressure gauges, transmitters, and other instrumentation. mss sp99 pdf
These components are typically found in:
Lists acceptable materials that comply with ASTM specifications:
While you may not print 40 pages, print the (typically Appendix A) and tape it to your workstation or inside your tool case.
A reliable source for engineering standards. Covers small valves and manifold valves designed for
The standard defines how manufacturers must determine the Pressure-Temperature (P-T) ratings for instrument valves. These ratings are heavily dependent on the body material (e.g., 316 Stainless Steel, Carbon Steel, Monel) and the sealing materials (PTFE, PEEK, Graphite). 2. Design and Construction
Needle valves, ball valves, check valves, plug valves, and packless valves. Scope of the MSS SP-99 Standard
| Standard | Focus Area | Key Difference | | :--- | :--- | :--- | | | Instrument valves & fittings (small bore) | Specifically for instrumentation, gauges, and transmitters | | ASME B16.34 | Large industrial valves (gate, globe, check) | For main process lines, not instrument connections | | ISO 17292 | Metal ball valves for petroleum and petrochemical | Broader valve types, not instrument-specific | | API 6A | Wellhead and Christmas tree equipment | For upstream oil & gas, much higher pressures |
“Why measure twice?” he scoffed. “My eye is true.” A reliable source for engineering standards
Purchasing an official copy ensures you receive the latest revisions, errata sheet updates, and a licensed document that satisfies regulatory audits.
Understanding MSS SP-99: The Standard for Instrument Valves The MSS SP-99 standard is a critical document for engineers, technicians, and procurement professionals working with instrumentation and piping systems. Published by the Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry, this standard dictates the essential design and manufacturing criteria for small valves used in instrument isolation and control.