Apparatus for generating ammonia by synthesising oxygen and nitrogen (chemical processing equipment); apparatus for generating hydrogen and optionally carbon monoxide, in particular synthetic gas from light or heavy hydrocarbons (chemical processing equipment); apparatus for generating nitrogen and optionally oxygen or argon by air separation, in particular cryogenic air separation (industrial treatment installations); evaporators, in particular for generating water vapour; heat exchangers, other than parts of machines, in particular for heating or cooling gases or liquids, in particular with quenching tanks; reactors, in particular for gas-gas-reactions, in particular thermal and/or catalytic reactions, in particular designed for high compressive loads, in particular for generating synthetic gases; waste traps, in particular for gas purification, in particular by adsorption using pressure and/or temperature or for gas scrubbing; gas scrubbing and purification apparatus; distillation apparatus, in particular distillation columns for physical separation of fractions, in particular refraction columns; refrigerating machines; regulating and safety accessories for gas pipes; water purifying apparatus; installations for generating ammonia containing one or several of the aforesaid apparatus (chemical processing equipment)