70-Kv Pyrex insulator

70-Kv. Pyrex Insulator

A one-piece, 70-kv., Pyrex insulator has just been released for sale by the Corning Glass Works. The successful manufacture of this insulator weighing 35 lb. and pressed in one solid piece, represents a distinct advancement in the art of manufacturing pressed dielectrics. The manufacture of Pyrex insulators of this size on a commercial basis is possible and successful only because of the special properties of the material used in making Pyrex products. Its low co-efficient of thermal expansion permits a very fine degree of annealing, which can be easily controlled in manufacture and checked by inspection in polarized light. The addition of this insulator to the Pyrex line makes Pyrex insulators available for operating voltages between 6,600 and 70,000.

The qualities of transparency, giving visual indication of the condition of the insulator at any life interval, resistance to power arcs and impulse lightning voltage, elimination of corona and its attendant radio interferences, one-piece construction, which characterize Pyrex insulator at any life, internal resistance found in this new insulator.