 |
| pipe section: 27 phrases in 17 subjects |
| Astronautics | 1 |
| Automobiles | 1 |
| Construction | 2 |
| Drilling | 1 |
| Energy industry | 2 |
| General | 1 |
| Hydrology | 1 |
| Mathematics | 2 |
| Metallurgy | 1 |
| Mining | 1 |
| Natural resourses and wildlife conservation | 1 |
| Nuclear and fusion power | 1 |
| Oil / petroleum | 1 |
| Oil and gas | 1 |
| Pipelines | 1 |
| Technology | 8 |
| Thermal engineering | 1 |