 In addition, a well-designed system will often use two 45° elbows instead of one 90° elbow (even a sweep 90° elbow) to reduce flow disruption as much as possible.Central vacuum system inlet fittings are intentionally designed with a tighter radius of curvature than those of other bends in the system.If vacuumed debris becomes stuck it will jam at the inlet, where it is easy to find and remove.