A 15 kv cable joint is enclosed within two half shells filled with sealant material. Displacement or thermal expansion of the sealant is accommodated by various configurations of stress cones that have apertures or surfaces that are flexible and arranged to maintain pressure on the sealant for example...http://www.google.fr/patents/US5900585?utm_source=gb-gplus-shareBrevet US5900585 - Electrical interconnections
