Expansion valve

An expansion valve is a valve used for different purposes:

Steam engines

A valve used to control the expansion of steam:

• Expansion valve (steam engine)
  • The best-known of these was the Meyer expansion valve, the invention of Jean-Jacques Meyer

Thermodynamics

A valve used to expand a gas, for thermodynamic cooling purposes in either:

• Joule-Thomson cooler
• heat pump

Also

• Thermal expansion valve, a component in refrigeration and air conditioning systems