L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des

L'air Liquide

A Nimal Liyanage

Jean-Marie Friedt

Kazuo Yokogi

Eiichi Ozawa

Henri Chevrel

Alain Boireau

A method of detecting a malfunction or failure of a pressure regulator in a corrosive or reactive gas distribution system while in use involves continuously measuring or monitoring the output pressure of the pressure regulator, both in the presence and the absence of gas flow. The onset of a malfunction of the pressure regulator can be predicted when the differential output pressure between flowing and non-flowing gas fluctuates highly and increases gradually. Failure of the pressure regulator or of the total system is detected when the differential output pressure in the presence and absence of flowing gas exceeds some experimentally determined value.

Method and system for assessing the operating condition of a pressure

A process for welding stainless steel tubing in the presence of an inert gas comprising a silicon base gas, in particular silane SiH.sub.4. During the welding operation, a suitable quantity of silicon is deposited by chemical vapor deposition at the weld joint to significantly improve the corrosion resistance of the weld.

Corrosion resistant welding of stainless steel

Growing community of inventors

Chiyoda, Japan

A Nimal Liyanage