For ducts smaller than 0.6 m use venturi pipe length 0.6 m.
For ducts between 0.6 and 1.3 m use venturi pipe length 1.5 m.
For ducts over 1.4 m use venturi pipe length 2.8 m.
VR-0.6M Venturi pipe 0.6 meter for UG-3
VR-1.5M Venturi pipe 1.5 meter for UG-3
VR-2.8M Venturi pipe 2.8 meter for UG-3
