Cast Iron Manhole Valve Kian Sanat Pasargard

Manholes are human pits that connect multiple networks and direct them to one side.
These valves are used for various types of water, electricity, sewage and telephone systems, and are in fact a way to make it easier for humans to access and inspect and fix problems.
The drainage valve and drain should have a polished inner layer of light, with a minimum brightness of the interior and a dark exterior wall.
The manholes of the wastewater must be such that they are highly resistant to the reaction with acids and alkali because of the many acidic gases in the wastewater.
A standard drainage check valve should have a smooth and regular surface to prevent adhesion of environmental contaminants to the exterior wall and to be impermeable.

What is the reason for the rounded valves?
One of the questions that may come up to you is why even though the rectangular valves on the sidewalks or the streets are more shaped, round valves are used instead of rectangular ones, or technically better than what the sewer valve looks like. , Square or circle?

This question, one of Microsoft's most popular questions in job interviews, has many answers, including:
-If the valve is round, it will never fall into the manhole if the door is open, but if it is a square valve, the valve may fall into a square manhole.- The round door moves easily and rolls-The cylinder is more resistant to ground pressure than the cube, taking this into account and making the pipes and valves round, and the lid is also designed round. It should also be noted that it is easier to dig a round hole and other reasons that may come to your mind are true, but the ones listed above are among the key design elements of valves.