MIL-I-631D

Abstract

This specification covers only the basic characteristics required by the synthetic insulation material, as such, and the methods suited to their satisfactory determination. <br>Electrical insulation shall be of the following types, as specified (see <a>6.2</a>): <br>Type A - Polyethylene. <br>Type B - Cellulose acetate butyrate. <br>Type C - Cellulose acetate or cellulose triacetate. <br>Type D - Ethyl cellulose. <br>Type E - Vinylidene chloride copolymer. <br>Type F - Polyvinyl chloride and its copolymers. <br>Type G - Polyethylene terephthalate. <br>Electrical insulation shall be furnished in the following forms, as specified (see <a>6.2</a>): <br>Form F - Film, in rolls (types B, C, D, and G only). <br>Form S - Sheet, fiat or in rolls. <br>Form T Tape. <br>Subform T_f - Film tape (types B, C, D and G only). <br>Subform T_s - Sheet tape. <br>Form U Tubing (see <a>6.7</a>) <br>Subform U_a - American-wire-gage size (AWG size) (types A, E and F only). <br>Subform U_b - Cable-end-sealing size (type F only). (see <a>6.8</a>) <br>Type F electrical insulation shall be furnished in the following grades, as specified (see <a>6.2</a>): <br>Grade a - General purpose. <br>Grade b - Low temperature (form U only). <br>Grade c - High temperature (form U only). <br>Electrical insulation shall be furnished in the following classes, as specified (see <a>6.2</a>): <br>Class I - Fungus resistance required. <br>Class II - Fungus resistance not required. <br>Type F, form U tubing shall be furnished in the following category: <br>Category 1 - Flame resistance required. <b><u>Intended Use:</u></b> This type of material is intended for ultra high-frequency applications. It possesses excellent electrical properties which remain practically constant oyer a wide range of frequencies, temperatures, and humidities, and has a very low loss factor. This type of material is intended for applications requiring a good dielectric strength, fairly low loss factor, good moisture resistance, and good insulation resistance. This type of material is intended for applications requiring good dielectric strength, fairly low loss factor, and a relatively high degree of heat resistance with some sacrifice in moisture resistance. This type of material is intended for radio-frequency applications requiring very good dry dielectric strength, fairly low loss factor, and fair moisture resistance. This type of material is intended for applications having excellent mechanical strength and excellent bursting strength. It is intended for general-purpose electrical applications but is more rigid than type F. This type of material is intended as a high-elongation, elastic material with good electrical properties, suitable as an alternate for rubber insulating tape in cable or other applications. This type of material is intended as a high-elongation, elastic material similar to type F, grade a, with less rigidity at low temperatures and other characteristics required for aeronautical applications. This type of material is intended as a high-elongation, elastic material similar to type F, grade a, but suitable for operation at higher temperatures (105&#176;C.). This type of material is intended for applications requiring good dielectric strength, fairly low loss factor, excellent mechanical strength and heat resistance. <br>