To ensure compatibility of piping fittings manufactured by various manufacturers globally, American Society of Mechanical Engineers has devised dimensional standards for various piping fittings. These are the most used dimensional standards in word for piping. They cover various fittings like pipes, tees, elbows, reducers, flanges, crosses and many other fittings. Here is a comprehensive list of such piping dimensional standards.
| Sr. | Number | Title |
| 1 | B1.20.1 | Pipe Threads, General Purpose (Inch) |
| 2 | B1.20.3 | Dryseal Pipe Threads (Inch) |
| 3 | B16.1 | Cast Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250 |
| 4 | B16.3 | Malleable Iron Threaded Fittings: Classes 150 and 300 |
| 5 | B16.4 | Gray Iron Threaded Fittings: Classes 125 and 250 |
| 6 | B16.5 | Pipe Flanges and Flanged Fittings NPS 1/2 Through NPS 24 Metric/Inch Standard |
| 7 | B16.9 | Factory-Made Wrought Buttwelding Fittings |
| 8 | B16.10 | Face-to-Face and End-to-End Dimensions of Valves |
| 9 | B16.11 | Forged Fittings, Socket-Welding and Threaded |
| 10 | B16.12 | Cast Iron Threaded Drainage Fittings |
| 11 | B16.14 | Ferrous Pipe Plugs, Bushings, and Locknuts With Pipe Threads |
| 12 | B16.20 | Metallic Gaskets for Pipe Flanges: Ring-Joint, Spiral-Wound, and Jacketed |
| 13 | B16.21 | Nonmetallic Flat Gaskets for Pipe Flanges |
| 14 | B16.25 | Buttwelding Ends |
| 15 | B16.28 | Wrought Steel Buttwelding Short Radius Elbows and Returns |
| 16 | B16.34 | Valves : Flanged, Threaded, and Welding End |
| 17 | B16.36 | Orifice Flanges |
| 18 | B16.38 | Large Metallic Valves for Gas Distribution (Manually Operated, NPS 21/2 to 12, 125 psig Maximum) |
| 19 | B16.39 | Malleable Iron Threaded Pipe Unions |
| 20 | B16.42 | Ductile Iron Pipe Flanges and Flanged Fittings, Classes 150 and 300 |
| 21 | B16.47 | Large Diameter Steel Flanges (NPS 26 Through NPS 60) |
| 22 | B16.48 | Steel Line Blanks |
| 23 | B36.10 | Welded and Seamless Wrought Steel Pipe |
| 24 | B36.19 | Stainless Steel Pipe |