When should the pressure in the two cylinders be equalized before disconnecting the high-pressure hose in a rapid intervention pack?

When should the pressure in the two cylinders be equalized before disconnecting the high-pressure hose in a rapid intervention pack?

• A. Before initiating air supply
• B. Immediately after connecting
• C. After pressure in the two cylinders has equalized
• D. After the victim starts breathing

Answer: (C)

Equalizing the pressure between the two cylinders before disconnecting the high-pressure hose ensures a safe, controlled separation. When two pressurized sources are linked, gas will move from the higher-pressure side to the lower-pressure side if the connection is disturbed. Disconnecting with a pressure difference can unleash an unexpected surge of air, cause a hose or fitting to recoil, or allow backflow that could compromise the equipment or the rescue. Waiting for the pressures to balance means both sides are at the same level, the flow path is momentarily stable, and the hose can be detached without a dangerous pressure impulse. This step is about equipment safety and reliability, not about the victim’s breathing, so it should occur after equalization rather than after breathing begins or before any air has been supplied.

Equalizing the pressure between the two cylinders before disconnecting the high-pressure hose ensures a safe, controlled separation. When two pressurized sources are linked, gas will move from the higher-pressure side to the lower-pressure side if the connection is disturbed. Disconnecting with a pressure difference can unleash an unexpected surge of air, cause a hose or fitting to recoil, or allow backflow that could compromise the equipment or the rescue. Waiting for the pressures to balance means both sides are at the same level, the flow path is momentarily stable, and the hose can be detached without a dangerous pressure impulse. This step is about equipment safety and reliability, not about the victim’s breathing, so it should occur after equalization rather than after breathing begins or before any air has been supplied.