# Professional Capping (DD-339)

> The Reel describes crews putting out gas fires by lowering a heat-resistant steel dome over the flames with heavy machinery, cutting off oxygen so the leak can then be capped or vented. Firefighting for wells and gas lines also uses water, chemicals and, for large well fires, explosives, before a cap is fitted. The footage shows a dome being lowered onto a fire.

- Department: Tech
- First published: 2024-10-06
- Last updated: 2024-10-06
- Permalink: https://detailenjoyer.com/case/professional-capping/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-339-F01**: Removing oxygen stops a fire. _(Write-up · Exhibit A (Smothering))_
- **DD-339-F02**: The Reel shows a steel dome. _(Write-up · Exhibit B (Dome))_

## Write-up

Crews lower a steel dome over a burning gas leak. Cutting off oxygen puts out the flames.

1. **Smothering**: Removing oxygen stops a fire.
2. **Dome**: The Reel shows a steel dome.
3. **Heavy machinery**: Machines position equipment.
4. **Capping**: Leaks are then capped.
5. **Other methods**: Explosives can snuff well fires.

## Related case files

- [Not So Well (DD-719)](https://detailenjoyer.com/case/not-so-well/): I linked more on oil wells

## Reel vs. record

- **Note**: I could not confirm how widely domes are used; I kept the Reel's description and attributed it.

## Video: Professional Capping: Crews Lower a Steel Dome Over a Burning Gas Leak

- Duration: 22.3 s · Published: 2024-10-06
- File: https://detailenjoyer.com/assets/videos/DAyhSI4pxKr.mp4

### Transcript

Did you know stopping gas line fires with domes involves placing a large heat resistant steel dome over the burning gas to suffocate the fire by cutting off its oxygen supply. These domes are designed to withstand intense heat and can be lowered onto the fire using cranes or other heavy machinery. Once the dome is in place, it traps the escaping gas, preventing it from fueling the flames while allowing workers to either cap the leak or vent the gas safely. NOW YOU KNOW!

## Questions & answers

**Q: What does the dome remove?**  
A: Fire triangle. _(Source: Write-up · Exhibit A (Smothering) · Wikipedia: Oil well fire)_

**Q: What lowers the dome?**  
A: Cranes. _(Source: Write-up · Exhibit B (Dome) · Wikipedia: Oil well fire)_

**Q: What comes after the fire is out?**  
A: Stop the leak. _(Source: Write-up · Exhibit C (Heavy machinery) · Wikipedia: Oil well fire)_

**Q: What else snuffs large well fires?**  
A: Blast removes oxygen. _(Source: Write-up · Exhibit D (Capping) · Wikipedia: Oil well fire)_

**Q: What must the dome resist?**  
A: Heat resistant. _(Source: Write-up · Exhibit E (Other methods) · Wikipedia: Oil well fire)_

## Sources

- [Wikipedia: Oil well fire](https://en.wikipedia.org/wiki/Oil_well_fire)

## Cite this case file

Easterling, Marcus. "Professional Capping." The Detail Department (DetailEnjoyer), case file DD-339, last updated Oct 6, 2024. https://detailenjoyer.com/case/professional-capping/