Abstract: The invention relates to a process for producing a diagram of an installation using apparatuses, each apparatus being supplied with gas, comprising: the consultation of one or more databases (5) comprising, for each apparatus, data on the flow rate, the nature, the purity of the gas supplying the apparatus, and the supply pressure of that gas for that apparatus, the selection, for each apparatus, of a value, or of a limit value, of duration or of frequency of use, the calculation, for each apparatus, of the consumption, or of the limit consumption, according to the utilisation value and to the flow rate data, the calculation, for each gas and for each gas purity, of the total of the consumptions of all of the apparatuses, the indication of technical constraints, the consultation of a database (5) for proposing, for each gas and each gas purity, a packaging, as a function of the consumption and of the technical constraints relating to the storage of the gas and/or to their delivery.

Abstract: The line of gas to be analyzed, the "zero" gas line and calibration gas line are each provided with a restriction operating in sonic rate supplying a nominal constant flow and downstream, have a discharge duct provided with a flow regulator. The nominal flows in the first and second lines are higher than the given flow supplied to the analyzer so that during each of the calibration and analysis steps, the whole of the circuit portion of the device is permanently flushed with the nominal gas of the line and/or by a portion of the recirculated flow of gas originating from another line.

Abstract: A pressure reducer, especially adapted for the supply of very pure gas in the electronics industry, which comprises a final stage having an inlet, pressure-reducing means and a low-pressure outlet. A filter having a filtration threshold lower than a micron is interposed between the pressure-reducing means and the low pressure outlet.

Abstract: The tap for a cylinder of gas under pressure is of the type comprising a body adapted to be fixed on a cylinder head (9) with a gas flow passage (10-13) provided with a valve (12) having a rod (14) slidable through a sealing bellows (17) and connected to a rod (21) of a pneumatic control piston (24) with provision of an opposing spring (28) for biasing the piston to a position for closing the valve (12). Manual means (31-32-33) are provided for axially shifting the piston (24) with an abutment in a position for closing the valve (12). The tap is particularly adapted to the transfer of gases having degrees of toxicity.

Abstract: In a gas flow regulating valve, the needle (37) axially shifted by a rod (40) includes a recess (70) which is of variable depth and cooperates with an expanding sealing element (43). The valve is provided with a safety closure means comprising a valve member (33) which has a spring (35) and whose displacements are controlled by a free connection tube (30).

Abstract: An installation for the delivery of a gas of high purity under a constant pressure from either of two vessels each of which is connected to a utilization outlet via a separate supply pipe and a switching system. A switching control system acts on two high-pressure valves, one for each vessel, downstream of which is situated a single pressure regulator which controls the outlet gas pressure. The valves are actuated by an auxiliary low-pressure gas via a pneumatic memory and two detectors measuring the pressure prevailing in the two gas vessels.

Abstract: The compounds of the formula: ##SPC1##In which Y represents a chlorine atom or an alkoxy, dialkylaminoalkoxy, pyridylalkoxy group, R.sub.1 and R.sub.2 are identical or different substituents and represent alkyl or alkoxycarbonylalkyl groups, substituted or unsubstituted phenyl groups or form together with the nitrogen atom to which they are attached, a heterocyclic ring which may contain another hetero-atom, R.sub.3 and R.sub.4 are identical or different substituents and represent alkyl groups or form, together with the nitrogen atom to which they are attached, a heterocyclic ring which may contain another hetero-atom; process for their preparation; medicaments comprising such compounds or salts thereof, and their use in the treatment of human beings.The present invention relates to new pyrimidines, to their use as medicaments on account of their spasmolytic, coronary dilator and hypoglycemiant properties and to their preparation.