A device for regulating pressure and/or mass flow of a gaseous or liquid fluid conveyed through a line in a space propulsion system includes a first, piezoelectrically actuatable regulating valve and at least two second, magnetically actuatable regulating valves. The regulating valves are connected to each other and to a line input in such a way that in a nominal mode the pressure and the mass flow of the fluid can be set by the first regulating valve, and a connection or isolation of the first regulating valve with or from the line input can be produced by the second regulating valves. In an emergency mode the pressure and the mass flow of the fluid can be set by the second regulating valves.

A slurry-transporting facility equipped with a plurality of pump-equipment circuits, whereby a stop of slurry supply to a transport destination at the time of switchover between the pump-equipment circuits for use is prevented to make an efficient operation possible. The slurry-transporting facility includes: pipe arrangements which branch out from a feed tank into the plurality of circuits; a transport pump provided in each of the pipe arrangement; a first valve provided upstream from the transport pump; a second valve provided downstream from the transport pump; and a uniting pipe arrangement formed by joining of the pipe arrangements at a predetermined position and connected to a LT heater. The uniting pipe arrangement is provided with a third valve configured to control the transportation of ore slurry to the LT heater and a pressure gauge configured to measure a pressure in the uniting pipe arrangement.

A variable flow rate gas control valve for use in consumer and commercial appliances is presented. The valve utilizes two or more solenoids to control the operating position of two different valve members whose orifices are sized in an exponential relationship with one another. By opening one or more of the valving members in various combinations, a variable flow rate of gaseous fuel may be controlled in integer multiple steps from full off to full on. The solenoid configurations may be in line, opposing, or symmetrical about an axis of the valve. The number of unique flow rates (F) is related to the number of solenoids (N) as F=2.sup.N. The relationship between the size (S) of the individual gas control orifices for each of the solenoids is related to N by the relationship S=2.sup.n1 for each individual gas control orifice (n) numbered 1 to N.

The invention relates to an electromagnetically actuatable gas valve for metering a gaseous fuel into a suction tract of a motor, in particular a gas or diesel gas motor, comprising a valve seat (1) which is designed as a flat seat and which has multiple annular webs (3) that are arranged in a concentric manner and are connected via at least one radially running web (4) in order to delimit circular or semicircular through-flow openings (2). The electromagnetically actuatable gas valve further comprises a movable valve plate (5) which sealingly interacts with the valve seat (1) and which has multiple annular sealing webs (6) that are arranged in a concentric manner and can be brought into an overlapping arrangement with the circular or semicircular through-flow openings (2) of the valve seat (1). According to the invention, the rigidity of the valve seat (1) and/or the valve plate (5) is substantially constant in the radial direction, the rigidity of the valve seat (1) being greater than the rigidity of the valve plate (5). The invention further relates to a method for increasing the seal of an electromagnetically actuatable gas valve.