Gas Balloon Valve

There are several types of valves used in gas balloons.  The three principal types are the French with a double clack and the German with a single clack.  Clack is the valve door that is opened.  The third type of valve is the new parachute type valve that uses balloon fabric instead of a metal or wood valve.

 The valves operate by pulling on a valve line.  The clack or valve plate are held in place by springs or rubber band that exert pressure on the base of the valve  to cause and automatic closing and sealing of the valve when the valve line is released.  The metal single clack valves have a thin seal between the plates to insure a gas tight seal.

The fabric valve is held in place by the force of the lifting gas.  The valve is centered using centering lines.  It is used as the primary deflation port for the envelope also.

The valve size is normally set 1/30 of the diameter of the envelope diameter.

Here is a diagram of a wood double clack valve.

Examples of the valve being used today include:

French Double Clack Wood	Metal Single Clack	Fabric Valve