| Elbow | ASME B16.9, ASME B16.11, MSS SP-75 | Visual, Dimensional, NDT | NPS 1/2 – 48, Schedule 5 – XXS | Butt-welded | Changes direction of pipeline by 45° or 90° |
| Tee | ASME B16.9, ASME B16.11, MSS SP-75 | Visual, Dimensional, Hydrostatic | NPS 1/2 – 48, Schedule 5 – XXS | Butt-welded | Divides flow direction into two or more paths |
| Reducer | ASME B16.9, ASME B16.11, MSS SP-75 | Visual, Dimensional, NDT | NPS 1/2 – 48, Schedule 5 – XXS | Butt-welded | Connects pipes of different diameters |
| Coupling | ASME B16.11, MSS SP-83, MSS SP-114 | Visual, Dimensional | NPS 1/4 – 4, Schedule 10 – 160 | Threaded/socket | Connects two pipes end-to-end |
| Union | ASME B16.11, MSS SP-83, MSS SP-117 | Visual, Dimensional | NPS 1/8 – 4, Schedule 40 – 160 | Threaded/socket | Easily disassembles two pipes |
| Cross | ASME B16.9, ASME B16.11, MSS SP-75 | Visual, Dimensional, Hydrostatic | NPS 1/2 – 36, Schedule 5 – XXS | Butt-welded | Branches pipes at right angles |
| Cap | ASME B16.9, ASME B16.11, MSS SP-75 | Visual, Dimensional | NPS 1/2 – 48, Schedule 5 – XXS | Butt-welded | Closes the end of a pipe |
| Stub End | ASME B16.9, ASME B16.11, MSS SP-75 | Visual, Dimensional | NPS 1/2 – 36, Schedule 5 – XXS | Butt-welded | Used with lap joint flanges for alignment |
| Bend | ASME B16.9, ASME B16.49 | Visual, Dimensional, NDT | NPS 1/2 – 24, Schedule 10 – XXS | Butt-welded | Changes direction of pipeline gradually |
| Nipple | ASME B16.11, MSS SP-95 | Visual, Dimensional | NPS 1/8 – 4, Schedule 40 – 160 | Threaded/socket | Short length of pipe used to extend or connect |
| Plug | ASME B16.11, MSS SP-114 | Visual, Dimensional | NPS 1/8 – 4, Schedule 40 – 160 | Threaded/socket | Closes the end of a threaded pipe |
| Olet | MSS SP-97, ASME B16.11 | Visual, Dimensional, NDT | NPS 1/8 – 24, Schedule 10 – XXS | Socket/welded | Branch connection in a run of pipe |
