Helium Tank

Breathing directly from a pressurized gas cylinder can cause catastrophic lung rupture and death. The tank valve must be NEARLY CLOSED before opening the hose valve, allowing only minimal flow through the regulator. Never rely solely on the regulator—always maintain tank valve control. If you feel ANY pressure sensation or discomfort, immediately stop inhalation.

Helium displaces oxygen in the lungs, creating asphyxiation risk. Take several deep breaths of normal air before inhaling helium. Do NOT hold your breath with helium. Do NOT inhale helium more than once without breathing normally for several minutes. Watch for signs of oxygen deprivation: dizziness, confusion, or loss of coordination.

DO NOT allow students to inhale helium under any circumstances. The risks are too great for unsupervised use, and liability concerns are significant. This demonstration should only be performed by trained instructors who understand the hazards and proper safety protocols.

Use the regulator/hose valve to START helium flow and the same valve to STOP flow immediately when your lungs feel comfortably full. Only after stopping helium flow should you close the tank valve completely. This sequence ensures you maintain control and can stop flow instantly if needed.

Purpose

Inhaling helium and speaking demonstrates how the speed of sound depends on gas density. The higher sound velocity in helium shifts vocal tract resonances (formants) upward, producing the characteristic "chipmunk" voice — while vocal cord frequency stays nearly unchanged.

Brown helium cylinder secured on a green wheeled cart with brass Victor regulator, clear flow meter tube, and flexible tubing at top

Close-up of brass Victor regulator with 0-4000 PSI gauge, graduated flow meter tube, hose valve on left, and tank valve on right

Figure 1: Helium cylinder on transport cart with pressure regulator, flow meter, and flexible tubing for controlled inhalation.

Figure 2: Close-up of the dual-valve system: tank valve (right, on cylinder) and hose/regulator valve (left, with tubing). The flow meter float often sticks — do not rely on it for safety.

Danger: Lung Overinflation Hazard

Danger: Asphyxiation Risk

Warning: Students Must Not Participate

Warning: Proper Valve Sequence

Purpose

Safety Warnings

Danger: Lung Overinflation Hazard

Danger: Asphyxiation Risk

Warning: Students Must Not Participate

Warning: Proper Valve Sequence

Purpose