摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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).
摘要:
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.These compounds, derived from 5-methylthio-pyrimidine, may be represented by the general formula: ##SPC2##In which Y represents a chlorine atom or an alkoxy, dialkylaminoalkoxy or pyridylalkoxy group, the alkoxy and alkyl groups preferably containing 1 to 4 carbon atoms, R.sub.1 and R.sub.2 are identical or different substituents and represent alkyl, alkoxycarbonylalkyl, substituted or unsubstituted phenyl or benzyl groups or form, together with the nitrogen atom to which they are attached, a heterocyclic ring which may contain another hetero-atom, the alkyl and alkoxy groups preferably containing 1 to 4 carbon atoms, R.sub.3 and R.sub.4 are identical or different substituents and represent alkyl groups preferably containing 1 to 4 carbon atoms or form, together with the nitrogen atom to which they are attached, a heterocyclic ring which may possibly contain another hetero-atom.Substituents of the phenyl group may be for example halogen atoms or alkyl, alkoxy or trihalomethyl groups.The compounds of formula (I) may be prepared for example by reacting a compound of the formula: ##SPC3##In which R.sub.1 and R.sub.2 have the same significance as above, with an ethylenediamine of the formula: ##EQU1## in which R.sub.3 and R.sub.4 have the same significance as above, and possibly replacing the remaining chlorine atom by an alkoxy, dialkylamino-alkoxy or pyridylalkoxy group.The reaction with the compound of formula (III) is preferably effected in a solvent, in the presence of an acid-absorbing agent, at a temperature between 20.degree.C. and 100.degree.C.The substitution of the remaining chlorine atom may be effected for example by the action of an alcoholate of an alkali metal or by the action of an excess of the corresponding alcohol and caustic potash at the refluxing temperature.
摘要:
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.