IPC Subgroup
E21B 34/12 operated by movement of casings or tubings
Introduced: January 1980
Last revised: January 2006
Full Title
Valve arrangements for boreholes or wells > in wells > operated by movement of casings or tubings
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS