fig1 to 4 show a gas flow valve 1 configured as a 2 / 2 - way valve . in accordance with a first embodiment shown in fig1 and 2 a cylindrical pressure vessel 7 is provided which is partly filled with a magnetic fluid 3 . outside of the pressure vessel 7 an electromagnet 9 in the form of a spool surrounds the part of the pressure vessel 7 filled with fluid . the electromagnet 9 is connected to a voltage source via leads 10 , making and breaking the connection of which depends on the position of a switch 12 . the cylindrical shape of the pressure vessel enables the valve 1 as well as its electromagnet 9 annularly surrounding the pressure vessel 7 and adjoining the latter to be simply fabricated . the inlet tube 11 extends through an opening in the shell surface area of the pressure vessel 7 into the magnetic fluid 3 and further bow - shaped above the fluid level 5 before finally protruding into the fluid 3 from above by its gas inlet 2 . due to part of the inlet tube 11 extending above the fluid level 5 no magnetic fluid 3 is able to flow from the pressure vessel 7 via the inlet tube 11 . a gas outlet 6 is located on the upper side 8 of the pressure vessel 7 . the functioning of the valve 1 will now be explained with respect to the fig1 and 2 . in fig1 the switch 12 is shown in the open condition , i . e . the electromagnet 9 is not connected to the voltage source and no magnetic field is generated . in this condition the magnetic fluid 3 is in the liquid phase , non - magnetic particles 4 being utmost finely dispersed in the magnetic fluid 3 . water is employed as the dispersion medium for the magnetic particles present in the magnetic fluid 3 . since the magnetic fluid 3 , as shown in fig1 is present in its liquid phase gas is able to flow via the inlet tube 11 and the gas inlet 2 through the fluid 3 . the portion of the interior of the pressure vessel 7 not filled with fluid 3 is filled with gas which is able to flow via the gas outlet 6 to a consumer . if the valve 1 is to be closed , the switch 12 , as shown in fig2 must also be closed so that the electromagnet 9 creates a magnetic field which acts on the magnetic fluid 3 . the magnetic field is thereby so strong that a change in viscosity of the magnetic fluid 3 and a phase transition from fluid to solid takes place . the non - magnetic particles present in the magnetic fluid 3 , preferably in the form of elastomers , are selected such that they receive a magnetic buoyancy in this state in the fluid 3 and are forced to the fluid level 5 where they are pressed together to form an additional barrier layer . the solidified magnetic fluid 3 permits no flow of gas and totally interrupts the gas flow . the further embodiment shown in the fig3 and 4 substantially corresponds to the embodiment explained heretofor except that instead of the electromagnet 9 a permanent magnet 19 is provided arranged vertically shiftable on the shell surface area of the pressure vessel 7 so that the shell surface area represents the mounting for the permanent magnet 19 . contrary to the embodiment described above the inlet tube 11 extends from below through a base surface area 13 of the pressure vessel 7 into the interior of the latter . in the open position of the valve 1 as shown in fig3 the permanent magnet 19 is arranged in the upper portion of the pressure vessel 7 . in this arrangement the magnetic field generated by the latter is so far removed from the magnetic fluid 3 that it is too weak to translate the fluid 3 present in the liquid phase as shown in fig3 into the solid phase or to attract it into portions having a stronger magnetic field . when , however , the permanent magnet 19 , as shown in fig4 is shifted downwards so that it surrounds the part of the pressure vessel 7 filled with fluid 3 , the actions in the fluid 3 as explained in conjunction with fig2 occur and the valve 1 assumes its closed position . the tensides also present in the fluid 3 are surface - active and prevent a kind of agglomeration of non - magnetic particles . it is also possible to configure valves 1 to incorporate both electromagnets 9 and permanent magnets 19 . fig5 and 6 show a gas flow valve 1 configured as a 3 / 2 - way valve . in accordance with this embodiment a cylindrical pressure vessel 7 is provided which is partly filled with a magnetic fluid 3 . protruding from above through openings in the upper side 8 of the pressure vessel 7 into this magnetic fluid 3 is a vent tube 14 and an inlet tube 11 having a gas inlet 2 , a gas outlet 6 being located on the upper side 8 of the pressure vessel 7 . outside of the pressure vessel 7 two electromagnets 9 , 16 in the form of spools are arranged such that one surrounds the region of the gas inlet 2 , the other the region of the gas inlet 23 . the electromagnets 9 and 16 are connected via leads 10 and 22 respectively to the voltage sources ( not shown ), the circuits being closed or interrupted depending on the position of the switches 12 , 21 . two of the possible four switching positions of the switches 12 , 21 are made use of to achieve the 3 / 2 - way valve , namely the switching position switch 12 open , switch 21 closed ( fig5 ) and the switching position switch 12 closed , switch 21 open ( fig6 ). the functioning of the 3 / 2 - way valve will now be explained with respect to the fig5 and 6 . in fig5 the circuit of the electromagnet 16 is closed , i . e . electromagnet 16 generates a magnetic field which attracts the magnetic fluid 3 into the region of the gas inlet 23 where it translates from the liquid phase into the solid phase . in this case too , the non - magnetic particles 4 dispersed in the liquid phase , as shown in fig2 are displaced by the magnetic field outwards , i . e . to the fluid surface represented by the inclined fluid level 5 , where they form an additional barrier layer . the solidified magnetic fluid 3 allows no flow of gas and totally seals off the vent tube 14 . between inlet tube 11 and gas outlet 6 the gas is able to flow unobstructed , valve 1 being open . in the position shown in fig6 the circuit of the electromagnet 9 is closed via the switch 12 , whereas the circuit of the electromagnet 16 is broken by the switch 21 . the electromagnet 9 generates a magnetic field which attracts the magnetic fluid 3 into the region of the gas inlet 2 so that the fluid there translates from the liquid phase into the solid phase . here too , the same as in the switching position shown in fig5 the barrier layer consists of non - magnetic particles 3 . the gas inflow through the inlet tube 11 is totally interrupted , valve 1 is closed . between gas outlet 6 and vent tube 14 gas is able to flow via the pressure vessel 7 , however , i . e . valve 1 is vented . the embodiment shown in fig7 to 10 corresponds substantially to the embodiment explained by way of fig5 and 6 , here however , instead of the vent tube 14 a second inlet tube 15 protrudes from above into the magnetic fluid 3 . the two inlet tubes 11 , 15 may be closed or opened or switched in common by a corresponding assigned magnetic field . the result is a valve 1 having a mixing function . in accordance with fig7 the inlet tube 15 is closed by the effect of the magnetic field of the electromagnet 16 . between the inlet tube 11 and the gas outlet 6 gas is able to flow unobstructed . fig8 shows the inverse function . in this case the inlet tube 11 is closed by the effect of the magnetic field of the electromagnet 9 and gas is able to flow unobstructed between inlet tube 15 and gas outlet 6 . in fig9 the circuits of both electromagnets 9 , 16 are closed . due to the effect of the magnetic fields the magnetic fluid 3 is attracted in each case to the inlet tubes 11 and 15 sealing off the gas inlets 2 and 23 totally due to the actions in the magnetic fluid 3 as already described , valve 1 being closed . part of the fluid 3 is displaced to the left - hand side of the pressure vessel 7 to close the gas inlet 23 by an inclined gas - tight fluid surface 5 . the remaining other part of the fluid 3 is displaced to the right - hand side of the pressure vessel 7 where it closes off the gas inlet 2 by an inclined gas - tight fluid surface . in fig1 the switches 12 and 21 are open , i . e . the electromagnets 9 and 16 generate no magnetic fields . the magnetic fluid 3 is present in the liquid phase and allows gases to flow from both gas inlets 2 , 23 to the gas outlet 6 . fig1 to 14 show an embodiment which substantially corresponds to the embodiment illustrated in fig7 to 10 . due to the change in the arrangement a valve 1 having a distribution function materializes . in this case the inlet tube 11 is arranged between two outlet tubes 17 , 18 so that should no magnetic field be applied the gas inlet 2 and ends 24 and 25 of the outlet tubes 17 and 18 respectively protrude into the magnetic fluid 3 . in fig1 closing the switch 21 closes the circuit of the electromagnet 16 , whereas the circuit of the electromagnet 9 is open . the electromagnet 16 generates a magnetic field in the region of the end 24 . due to the effect of the magnetic field the magnetic fluid 3 is attracted into this region where it solidifies . the aforementioned inner actions seal off the gas outlet 17 totally , whereas gas from the inlet tube 11 is able to flow via the outlet tube 18 from the pressure vessel 7 without needing to flow through magnetic fluid . fig1 shows the inverse function of valve 1 . in this case the outlet tube 18 is shut off by the magnetic field generated by the electromagnet 9 . from the inlet tube 11 gas is able to flow via the outlet tube 17 from the pressure vessel 7 . in fig1 the switches 12 and 21 are closed . the electromagnets 9 and 16 generate magnetic fields which attract the magnetic fluid 3 into the regions of the ends 24 and 25 , the fluid translating into the solid phase . the two outlet tubes 17 and 18 are totally shut off by the inner actions in the magnetic fluid as already described , valve 1 being in the blocking function . in fig1 the circuits of the electromagnets 9 and 16 are open so that no magnetic field effects the magnetic fluid 3 . as described in fig1 gas is able to flow from the inlet tube 11 through the fluid 3 and outlet tubes 17 , 18 . in this case the gas is distributed to the two outlet tubes 17 and 18 . fig1 and 16 show a further embodiment of a valve 1 configured as a multiway valve having a mixing function comprising four inlet tubes 11 , 15 , 26 and 27 and a gas outlet 6 . the way in which the valve 1 works corresponds substantially to that as already explained with respect to fig7 to 10 . shutting off or opening individual inlet tubes 11 , 15 , 26 , 27 is done by means of the electromagnet 9 being horizontally rotatable at a hemispherical lower part 13 &# 39 ; of the valve 1 about the vertical longitudinal axis of the pressure vessel 7 ( cf arrow a ) and / or being shiftably mounted about the lower end of the hemispherical lower part 13 &# 39 ; oscillatingly ( cf arrow b ). the corresponding guidance of the electromagnet 9 is not shown . the electromagnet 9 can be arrested in several positions or even continuously so . instead of the electromagnet 9 a permanent magnet may also be provided . in accordance with fig1 the annular electromagnet 9 is shiftably mounted by a guiding means ( not shown ) such that its magnetic field attains only the region of the gas inlet 2 . due to the effect of the magnetic field the solidified magnetic fluid 3 shuts off the inlet tube 15 . if the fluid level 5 is brought to the fluid level 5a by replenishing the fluid 3 via a filler tube ( not shown ) further inlet tubes are shut off , these being in the example inlet tubes 26 and 27 , depending on the fluid level 5a , the magnetic fluid 3 and the position of the electromagnet 9 . in the position shown in fig1 the electromagnet 9 extends around the lower part 13 &# 39 ; of the valve 1 . in this horizontal basic setting all lower tube ends of the inlet tubes 11 , 15 , 26 and 27 lie in the region of its magnetic field . the switch 12 of the circuit is opened and no magnetic field acts on the magnetic fluid 3 . as described above , in this case gas is able to flow from the inlet tubes 11 , 15 , 26 and 27 through the magnetic fluid 3 and through the gas outlet 6 from the pressure vessel 7 since valve 1 is totally opened . when , however , the switch 12 in this basic setting of the electromagnet 9 is closed , the magnetic fluid 3 solidifies due to the effect of the magnetic field of the electromagnet 9 as already described and seals off all inlet tubes 11 , 15 , 26 and 27 so that valve 1 is totally shut off . fig1 and 18 show the gas flow valve 1 as has already been explained with respect to fig1 and 16 . to change the fluid level 5 a gas - sealable filler tube 28 is introduced from above through the upper side 8 of the pressure vessel 7 sufficiently downwards so that it protrudes into the magnetic fluid 3 in the horizontal basic setting of the magnet 9 . the filler tube 28 is connected to a pumping system ( not shown ) and permits a continuous change in function of the valve 1 . depending on the position of the electromagnet 9 and the filling level 5 , one , two or three inlet tubes are thus sealed off . it is also possible to configure valves incorporating both electromagnets 9 and additional permanent magnets 19 . the multiway valves as described above are characterized by a single pressure vessel being sufficient since the magnetic fluid is drawn into a strong magnetic field so that predetermined inlet or outlet tubes can be opened or closed . in addition to this , however , multiway valves may also be produced by several of the valves already described , connected to each other and switched via corresponding drilled passageways . in addition at the input of each switch 12 , 21 a potentiometer may be arranged with which the amperage applied to the electromagnet 9 or 19 can be continuously varied . varying the amperage in turn varies the viscosity of the magnetic fluid 3 so that this too is continuously variable to allow more or less gas to flow through the valve 1 , thus achieving a continuously adjustable valve .