Figure 4 Blocked Conductor Longitudinal Water Blocked Conductors To achieve longitudinal water blocking, the interstices or spaces between the strands of conductors must be altered to prevent water from flowing freely down. The industry standard test for this is found in Reference 3. In this test, one end of the conductor is exposed to water under pressure, while the other end is checked for water leaking within certain length of time. Filling the interstices with a plastic compound. Using solid conductors having no interstices.
Strand Filling Strand filling compounds are either semi-conductive or insulating materials.
Some materials can be applied during manufacturing. Some can be pumped into short lengths of finished cable. Strand filling fills the interstices of the stranded conductor with material so water cannot run longitudinally down the conductor. Well designed strand filling compounds should have several properties. Dimensional stable over a wide range of temperatures.