Abstract: One end of a dual-ended housing is closed off by a plug formed of a first constituent which is a water-soluble material and a second constituent which is a thermosetting resin and forms a readily-frangible structure in the plug. An electrical switch which has an actuating plunger is set, in the housing against the plug, so that the latter holds the plunger depressed/retracted. Moisture expands the water-soluble material which, in turn, destroys the plug integrity and, subsequently, the plug is so weakened that the plunger breaks through the frangible structure to actuate the switch.

Abstract: A submersible machine has an electrically driven rotating mixer. The electric motor and hydraulic part are connected by a rotary shaft. The shaft end opposite from the hydraulic part is resiliently supported in a stator casing which surrounds the motor.

Abstract: A method and a device for installation of a mixer in a liquid tank is provided wherein the mixer is brought downwards into the tank along a guide which is pivotally attached in the upper part of the tank. During operation the reaction force from the impeller will cause the guide to pivot making the mixer take support against the tank wall.

Abstract: A pump for pumping and mixing of liquids containing suspensions comprises a housing having an impeller rotatable in both directions and a central inlet. The housing is provided with two outlets which are closed alternatively by a ball, depending on the rotation direction of the impeller.

Abstract: In larger sewage water systems, there is a risk that the water may become rotten due to lack of oxygen. According to the invention, this problem is solved by letting the pump in a pump station of the system act as an aerator as well as a transporter of the water. To aerate the water, the outlet of the pump is connected to a jet nozzle with an air intake. The aerated water is conveyed back to the pump station tank. The pump outlet may also be connected to the outlet pipe of the tank for discharging sewage water from the tank.