Silicone rubber insulated cables show virtuallycontinuous resistance to hot air at temperature up to 180 – 200 °C. Higher working temperatures can be achieved by special silicone rubber compounds which show good mechanical end electrical properties up to 250°C for several thousands hours ( for short periods of time they withstand also temperatures up to 300 °C ). Silicone rubber insulated cables are not generally recommended to applications exposes to overheated steam. Prolonged exposure to steam at temperatures above 130 – 140 °C attacks and finally destroys them.
Low temperature flexibility
Silicone rubber insulated cables present good electrical, mechanical properties and flexibility even at temperatures of -40 °C. These are not obtained by the use of special plasticisers nor at the expense of heat stability. Therefore silicone rubber insulated cables can be exposed to high and low temperature alternatively without damages.
Resistance to chemicals
Silicone rubber is severely attacked by alkalis, acids, liquid fuels, chlorinates hydrocarbons, esters, ketons and ethers. Silicone withstands aliphatic motors and gears oils well. It swells somewhat more in naphthenic oils, whereas aromatic oils, especially at temperatures over 140°C, usually render it unserviceable.