PURPOSE: To demonstrate the force created by freezing water.

DESCRIPTION: A pipe nipple with end caps is filled with water, sealed by tightening the ends, and dropped into a metal container of liquid nitrogen. Within about one minute the water freezes, expanding sufficiently to break the cast iron with a loud crack and a big cloud of vapor. The picture above left shows the apparatus, including items to use when holding the frozen pipe nipple. The photograph at the right shows a new nipple with end caps (upper left), a nipple that was blown into two parts, and a nipple that was blown into three parts by the force of the expanding ice.

Be careful to fill the nipple completely with water before immersing it in liquid nitrogen. If it does not explode, leave it alone; it may still be dangerous.

SUGGESTIONS:

REFERENCES: (PIRA 4C20.21)

EQUIPMENT: Cast iron pipe nipple with end caps, coffee can with water, liquid nitrogen in coffee can, gloves, and steel outer bucket with handle.

SETUP TIME: 5 min.