
17x30x7 oil seal. The seal should be pressed into place using a proper installation tool to avoid any damage to the sealing element.
There are three different types of manholes: shallow, normal and deep. “Normal” manholes are typically 4- to 5-feet deep and wide enough for the average person to fit in. Shallow manholes are 2- to 3-feet deep, often placed at the start of a sewer branch and in areas with low traffic. Manholes with a depth greater than 5-feet are considered deep and usually have an entry method like a ladder built-in, as well as a heavier cover.