I got tired of replacing the ever breaking screw clips that hold up some flexible ∅20mm PVC tubes with some network cables at home.
So i made two basic versions, one single and one dual.
Mine are printed in Taulman3D´s n-vent and i had 35% infill to make it rigid. One can decrease the amount of infill to make it more flexible and even use a larger diameter pipe.
While i haven´t tried any other diameters it probably works with diameters around 20-22mm.