MSS SP-85

Covers — cast (gray) iron globe and angle valves with flanged or threaded ends for general low-pressure water, steam, and utility service, including ratings, materials, dimensions, and testing.

Does NOT cover (exclusions) — the following are governed elsewhere:

• Bronze globe/angle/check valves → MSS SP-80.
• Steel valves for process/petroleum service → API 600 / 602.
• Flammable, toxic, or shock-loaded service where brittle cast iron is unsuitable → steel/ductile valve standards.

Gray cast iron is brittle; SP-85 valves are limited to mild, non-hazardous service.

SP-85 sets minimum requirements for cast iron globe/angle valves:

• Materials — gray cast iron body/bonnet with bronze or iron trim.
• Design & Ratings — Class 125/250 pressure-temperature ratings; standardized dimensions and end connections.
• Testing & Marking — shell and seat testing with acceptance leakage, plus marking per MSS SP-25.

MSS SP-85 standardizes cast iron globe and angle valves for low-pressure water, steam, and utility service, defining Class 125/250 ratings, materials, dimensions, and testing. It is the cast-iron companion to the bronze SP-80 standard.

Because gray cast iron is brittle, these valves are limited to mild, non-hazardous duty and are not appropriate for flammable, toxic, or shock-loaded service.

Engineering Note: Do not substitute a cast iron SP-85 valve into a line that can see thermal shock or hydraulic hammer — brittle failure of the body is the risk.