The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry is a non-profit technical association organized for development and improvement of industry, national and international codes and standards for: Valves, Valve Actuators, Valve Modification, Pipe Fittings, Pipe Hangers, Pipe Supports, Flanges and Associated Seals. Here is a list of standards devised by this Institute.
| Sr. | Number | Title |
| 1 | MSS-SP-6 | Standard Finishes for Contact Faces of Pipe Flanges and Connecting-End Flanges of Valves and Fittings |
| 2 | MSS-SP-9 | Spot Facing for Bronze, Iron and Steel Flanges |
| 3 | MSS-SP-25 | Standard Marking Systems for Valves, Fittings, Flanges, and Unions |
| 4 | MSS-SP-42 | Class 150 (PN 20) Corrosion Resistant Gate, Globe, Angle and Check Valves With Flanged and Butt Weld Ends |
| 5 | MSS-SP-43 | Wrought Stainless Steel Butt-Welding Fittings Including Reference to Other Corrosion Resistant Materials |
| 6 | MSS-SP-44 | Steel Pipe Line Flanges |
| 7 | MSS-SP-45 | Bypass and Drain Connections |
| 8 | MSS-SP-51 | Class 150LW Corrosion Resistant Flanges and Cast Flanged Fittings |
| 9 | MSS-SP-58 | Pipe Hangers and Supports |
| 10 | MSS-SP-65 | High Pressure Chemical Industry Flanges and Threaded Stubs for Use with Lens Gaskets |
| 11 | MSS-SP-69 | Pipe Hangers and Suports |
| 12 | MSS-SP-70 | Cast Iron Gate Valves, Flanged and Threaded Ends |
| 13 | MSS-SP-71 | Gray Iron Swing Check Valves, Flanged and Threaded Ends |
| 14 | MSS-SP-72 | Ball Valves With Flanged or Buttwelding Ends for General Service |
| 15 | MSS-SP-75 | Specifications for High Test Wrought Buttwelding Fittings |
| 16 | MSS-SP-79 | Socket-Welding Reducer Inserts |
| 17 | MSS-SP-81 | Stainless Steel, Bonnetless, Flanged, Knife Gate Valves |
| 18 | MSS-SP-83 | Class 3000 Steel Pipe Unions, Socket-Welding and Threaded |
| 19 | MSS-SP-85 | Gray Iron Globe and Angle Valves, Flanged and Threaded Ends |
| 20 | MSS-SP-88 | Diaphragm Type Valves |
| 21 | MSS-SP-95 | Swage(d) Nipples and Bull Plugs |
| 22 | MSS-SP-97 | Integrally Reinforced Forged Branch Outlet Fittings |