Heat insulated pipe laying system - stretches inner pipe after laying to lock into outer one using saturated steam

摘要

The system lays a pipeline comprising lengths of heat-insulated pipes, particularly for a district-heating system, in the ground. EAch pipe comprises inner and outer metal sections sliding in relation to each other, with an insulating layer between. The inner pipe is stretched and fixed in relation to the other pipe in the stretched state. After laying, the inner pipe is stretched, preferably by passing saturated steam through it, and automatically locks into position in the outer pipe at predetermined points.