Abstract: An automatic switchover valve includes first and second regulator valves arranged to oppose each other axially in a single housing, and ducted in a parallel configuration within the housing. Each regulator valve includes an inlet port, a diaphragm poppet valve, and a common outlet port. Each regulator valve includes structure for adjusting the pressure setting of the diaphragm poppet valve. During operation, the poppet valve of the first regulator valve is selectively adjustable between a first setting providing a first pressure P.sub.1, and a second setting providing a second pressure P.sub.2 less than P.sub.1 by an amount equal to 2 p. The poppet valve of the second regulator valve is preset at a reference pressure P.sub.R wherein P.sub.1 >P.sub.R >P.sub.2, and P.sub.1 -p=P.sub.R =P.sub.2 +p, and wherein p is greater than or equal to the incremental pressure characteristic of the regulator poppet valves.

Abstract: A gas cabinet for enclosing one or more compressed gas cylinders is ventilated for rapid removal of any gas leaked from the cylinders. The cabinet has a perforated plate as its floor which also serves as a fresh air inlet. Since the entire floor is used as the air inlet, the airflow through the interior of the cabinet is uniform and across the full width and depth of the cabinet, virtually eliminating dead areas or channels where leaked gas could accumulate. A tapered roof provides a smooth air handling transition to an exhaust port in the roof. The exhaust port may be connected to a plant ventilation system for removing the exhausted air from the cabinet.

Abstract: A hermetically sealable fluid containment assembly is provided. Fluids, such as compressed gases, are typically stored in a base container having a shoulder with a neck projecting outwardly from the shoulder. In accordance with the invention, a collar member generally surrounds the neck and rests upon the shoulder of the base container. A locking arrangement is provided to securely fasten the collar member to the base container. A closure member in the form of a protective cap engages the collar member. To prevent the leakage of fluid between the collar and the base container, a seal is provided between respectively engaging surfaces of the base container and the collar. The leakage of gas between the collar member and the closure member is also prevented by a second seal disposed between respective engaging surfaces of the closure member and the collar member.

Abstract: A process is disclosed for use in the manufacture of multilayer thin film integrated circuits for selective removal of specific layers, and a composition of matter useful in the process for selective etching of polysilicon and silicon nitrides during the manufacture of thin film integrated circuits. A multi-layer thin film integrated circuit is exposed to a plasma formed from a gaseous mixture of nitrous oxide and a fluoro compound. The nitrous oxide preferably comprises between 2.5% and 9.0% of the mixture and the fluoro compound preferably comprises between 91.0% and 97.5% of the mixture.