Extinguishing Nozzles (Voltage Interuptors) for use in high-voltage switches.

• Good electrical insulation
• High temperature resistance

The insulating or quenching nozzle of a high-voltage switch is a crucial component of a circuit-breaking unit. The quenching gas (SF6) flowing out of the arc chamber is directed in it and blown out into the upper area of the switch. Disconnection of the voltage switch results in an arc with the conterminal voltage which is quenched via the gas. The PTFE insulating nozzle of a high-voltage switch consists of a PTFE compound, which is completely resistant to chemicals (acids, alkalis), temperature-resistant to 260°C in continuous operation (short-term to 300°C), non-flammable and – very important for use in the switch – a tremendous insulator. A special filler is admixed with the PTFE. This is crucial for the switching performance and service life of the switch and also colours the nozzle. The composition of this filler is a closely guarded secret of every switch manufacturer. In order to minimise material consumption, the blanks are pre-pressed isostatically, sintered and then turned in the final shape.