Pipes for high temperature subterranean liquids - has steel tube with insulating and protecting sheaths and concrete cover

摘要

The pipe consists of an internal steel tube (1) with a suitable coefficient of expansion. This is surrounded by a sheath (12) of heat insulation. The next insulating layer (2) is wrapped in a sleeve of polyester (21) to resist damp. The final outer layer (3) is covered in concrete to give resistance to compression, the whole then being back-filled with earth. The internal tubes (1) are joined by welding. The weld is surrounded by an insulating jacket (20) and a protecting sleeve (22), which ensures a water tight seal. It is used for liquid temperatures in the region of 200 deg.C.