H-20 Reducer Top manholes are specially designed for installation in areas where vehicular traffic may be present. Utilizing a specially designed reducer, H-20 Highway Loading manholes are used in conjunction with grade rings, frame, and cover.
H-20 Highway Loading manholes are for use in areas where vehicular traffic may be present (roads, parking lots, loading dock areas) or where a low profile installation is required.
4', 5', and 6' [1.22, 1.52, and 1.80 m] diameter manholes.
Sizing Traffic Reducer Top Manholes
H-20 Highway Loading manholes are sized to be 12-inches [30.48 cm] below the finish grade. This allows standard grade rings / frame / cover systems to be used to bring the installation up to grade.
Image: Hamilton Kent