Special Features of Hemingray Pin Type
Distribution Line Insulators.

Dielectric Strength

It is generally known and has been proved repeatedly by standard tests that glass is of great dielectric strength. This quality is a characteristic of the material. The high dielectric strength of Hemingray Glass insulators is the result of the basic dielectrical characteristics of the material of which they are made. This insulating value is permanent -- it cannot deteriorate with age or condition of service.

Mechanical Strength

The new Hemingray glass possesses the features of mechanical strength desired in power line insulators. It is unaffected sudden temperature changes, it does not break easily and because of the many new design features Hemingray glass insulators will compare favorably in mechanical strength to that of other types of insulators designed for the same service.

Heat Shock Tested

The heat shock method of testing Hemingray glass insulators, coupled with a controlled annealing process, insures uniformity of product and eliminates the insulators that do not meet proper mechanical strength requirements.

Freedom from Deterioration and Aging

Hemingray Insulators are made of a material which is homogeneous in character, rather than from a substance composed of two or more materials whose co-efficients of expansion may be different. Hemingray Insulators being made of glass -- a homogeneous material with but one co-efficient of expansion -- are not subject to conflicting strains induced by the natural forces of heat and cold. Hemingray insulators after 40 years of known service are free from any sign of aging or deterioration.

Other Features

DESIGN -- Much time and study have been spent on the design of these new insulators. They are built to meet the needs of the Electric Light and Power Industry and many engineers of the larger utilities have co-operated in the development of these new designs.

TRANSPARENCY -- The new Hemingray line is transparent -- the glass is clear -- reducing inspection costs.