- Published: Saturday, 27 December 2014 11:38
- Written by Lance Hartley
- 3 - 4 crew
- Crew Leader
- 2 lengths 38 mm lay-flat hose
- Fog branch
- 45 kg gas bottle (completely vented for simulation purposes only)
Warning: Do not carry out this drill on actual gas cylinders. This drill for simulation purposes only. Ensure that full PPE + flash hood is donned.
- Ascertain if possible, the source of the gas leak (regulator - low pressure, vents sideways or downwards; in-line (pigtails) - high pressure, ; safety valve / cylinder head; vent sideways). The safety value will emit loud / shrill noise when venting.
- Bowl out one line, 2 or 3 lengths, of 38 mm hose. The safety crew should already have appropriate equipment established. (1 line-two lengths 38 mm hose using secondary water source; hose fully charged).
- Select water volume on branch (230 L per minute using Ackron)
- Signal water on, test branch. Position team safely - upwind of incident.
The appropriate strategy needs to be identified for the scenario (i.e. see (2) above.
If cylinder is venting via safety valve:
- Strategy would be to continue to cool cylinder(s). Appropriate water supply needs to be established. Using Ackron or similar branch, turn to fully on, select powercone spray pattern. (do not select jet as this could knock over the gas cylinder(s). Under Crew Leader supervision advance (from upwind) and cool cylinder(s) between shoulder and base (not neck as this action could extinguish the flame).
- When appropriate switch from powercone to fog pattern. When 'ontop' of the cylinder head, direct fog pattern to 'capture' and 'bend' flame down.Crew leader should be able to extend gloved hand around fog pattern to turn gas off. Crew to retreat safely under fog then power cone, continually cooling cylinder(s). Consider using ground monitors as an option if cooling is to ongoing.
If cylinder is venting via regulator: strategy would be to cool the gas cylinder(s) using a powercone spray pattern whilst advancing from upwind. When Crew Leader instructs, fog pattern on branch is to be selected.
Continue to advance. Situational awareness by all crew, noting that visibility will be very limited Crew to position to 'capture' flame in fog spray, ensuring that flame is not enclosed between fog pattern and wall. Using fog pattern to protect crew, crew to obtain position to turn off gas supply.
Note: Essential not to break fog pattern with structures or extended limbs. After closing gas tap, crew withdraw under fog and, changing back to powercone, continue cooling cylinders. If cylinder is venting via in-line hose: strategy would be the same as if the cylinder is venting via the regulator.