Abstract: The switching valve of a quick-operating slider system is an electrically operated stop valve. In the case of a required rapid shutoff, the coil (19) must be de-energized in a very short period of time in order to allow the switching valve (18) to open. For this purpose, a voltage-dependent resistor (33) is provided between the voltage source (25) and the coil (19), said resistor (33) having a high resistance below a switching voltage (Us), but a negligibly small resistance above the switching voltage. An auxiliary voltage source (35) is connected in parallel to the coil (19), the voltage of said auxiliary voltage source (35) being opposite to that of the voltage source (25). In this manner, the switching valve is rapidly opened both when a corresponding signal is received and in the case of power failure.
Abstract: A trigger circuit comprises a first series circuit (16) defined by an electronic switch (17) and an electromagnetic actuator (10). A second series circuit (18) defined by a resistor (19) and a sensor (20) responding to danger situations is arranged in parallel to said first series circuit (16). A tap (24) of said second series circuit (18) is connected with a control electrode (25) of said electronic switch (17). The circuit is of simple configuration and ensures a reliable switching behavior. Even when said sensor (20) is closed again, the trigger state is maintained.
Abstract: A shutoff device for shutting off liquids or gases comprises a device housing (10) and a device (13) movable in said housing (10), the device (13) being provided with an opening (14). For sealing purposes, annular sealing bodies (28) are provided which are supported in annular fluid cylinders (27). The contact surfaces (34) are coated with a hard-material layer (37,39) which is subjected to microfinishing. The sealing bodies (28) are yieldingly supported such that they are capable of following any deformation or displacement of the device (13). The sealing is particularly suitable for aggressive and abrasive media and solids-carrying media.