The ASTM B267 standard provides requirements and suggestions in the use of insulated wire coverings such as silk, nylon, cotton, and glass which can be verified at Lectromec.
The standard requires that, when present, an outer layer of covering must be wrapped in the direction opposite to the inner covering. This and other physical characteristic requirements can be verified via visual examination.
The tightness of the covering wrap on the wire/ cable bundle shall be such that it will endure a bend over a specified mandrel without exposing any of the interior wiring, as observed by an unaided eye. This can be verified by simple mechanical bend testing.
Recommendations are provided for the maximum operating temperature of each covering material and for the nominal outer diameters of the wrapped bundle construction including the covering material. These can be verified by thermal testing and physical inspection, respectively.
Contact Lectromec to determine an ideal test plan for your insulative wire coverings.