Careful consideration must be taken on the working conditions of Chemical Hose. If the assembly is constantly flexing, surging, or in a bent application, it could change the capabilities of the assembly. Bend guard, vacuum spring wires and armor guard protectors can be installed in some applications that will prolong the life of the hose assembly. Certainly media is a big factor in which product should be used. One factor to consider is: Permeation: Media that will diffuse through the liner wall and attack the exterior of the hose.