Сoaxial systems CLV (the pipe in pipe)
Coaxial systems are used in cases when it is necessary to reduce the weight of the system and the load on the foundation. And also when you want to reduce the time. Coaxial system - chimney type "pipe in pipe" consisting of the elements are located in the shaft made of stainless steel.
The difference between the previous system is that this one needs no foundation. The advantage is promptness and ease of installation works.
Hermeticity of the system is provided by silicone seals, which are more comfortable and more up-to-date alternative to silicone sealant.