A new type of moving petticoat pipe structure and petticoat pipe seal which fit for forced circulation way is introduced. A kind of flexible fastening of moving petticoat pipe is also recommended.

Torsional breekage, at the bottom of a flexible wheel has been found in the experiment , such breakage being strongly influenced by the dimension of fastening and assembly stresses .

The design of modular fixture with side fastening is a flexible combination system for the fixtures with the side joint of fundamental elements.