Medium Voltage Heat Shrink Joints-Conventional and next generation. Raychem developed highly specialized polymers for heat shrink joints suitable for plastic and paper cables upto 36 kV. For transition joints, a special oil barrier tubing is used to transform draining oil (MI) and non-draining oil (MIND) paper insulated cable into quasi-polymeric insulated cable with a radial field.   

The conventional design developed in 1980 was based on multiple layer tubing concept providing insulation and stress functions. The latest developed heat shrink joint is a single tubing (triple layer co-extruded) of adequate thickness which provides insulation for a particular voltage range.