Flexible metal hoses with their high temperature and resistance and easy bent structures are produced in two different versions depending on the corrugation types. 
1-Annular corrugation: Annular corrugated metal hose is made from longitudinally welded tubing but with the corrugations formed in parallel planes vertical to the axis of the hose.

 

2-Helical corrugation: Helical corrugated metal hose is also made from longitudinally welded tubing but with the corrugations formed in helix or spiral relative to the axis of the hose. 
Flexible metal hose depends on the profile and the distance between the corrugations as well as the wall thickness. Higher profiles with small distance between the corrugations provide more flexibility. in the same way,reducing the wall thickness also causes an increase in the flexibility,but in this case,the pressure resistance will be reduced. 
in order to increase the pressure resistance,flexible metal hoses are reinforced with single or multiple braiding. Braiding does not only prevent longitudinal expansion of the hose caused by interior pressure,but it can also absorb exterior tensile stress and provide protection of the exterior surface of the hose. 
Flexible metal hose can be used in all applications where high flexibility and tightness are required,due to its functional and constructional properties.Another advantage of corrugated hoses is the absorption of vibrations.