There are many everyday objects that we come across and never wonder about. From something as simple as a comb while grooming ourselves in the morning to the manholes we cross over as we walk down the roads. Have you ever wondered what goes behind making the cover of a manhole? Manhole covers date back to the era of ancient Rome when they were made of stone.
Manhole covers, as we all know are the removable lids atop a manhole, usually big enough for a person to pass through. They are used to access underground pipelines and vaults. They started off as slabs of stones and sometimes, pieces of wood and this continued till the 18th Century. In the 19th Century, modern ductile manhole covers were developed. For the last 200 years, manhole covers are made of cast iron in varied designs.
While circular manhole covers are what we frequently come across, manhole covers are also available in different shapes like rectangle and square and varied sizes. There are also triangular manhole covers in some parts of the world. Here are some interesting characteristics of different types of manhole covers:
- Choosing the right cover: When searching for the right manhole cover, many factors have to be considered. Construction, dimension specification, as well as the positioning of the manhole, have to be kept in mind while purchasing the manhole cover.
- Division as per weight: Different manhole covers weigh differently, depending on the load they have to deal with. A manhole cover on an airport runway will have to be much heavier than a cover on the road, whereas one on a pavement which has only pedestrians and cyclists is lighter.
- Locking of manhole covers: As an extra measure of security, manhole covers have the option of being locked up or welded, especially in case of manholes on roads where racing occurs. It may sound bizarre, but often manhole covers are stolen to be sold as metal scrap.
- Difference between shapes: A round manhole cover is often chosen because the chances of it falling through its circular opening are very low whereas it is possible with square covers. They are much smoother, have smaller surface area, are easily movable as well as easy to lock in place.
Ductile manhole covers and manhole frames are invisible products that make our life smoother. Made of cast iron, they are sturdy and essential for the running of any city. Govind Steel, a leading foundry in India constructs varied types of manhole covers and frames as well as manhole grates. They have different shapes, sizes and designs along with other cast iron and steel products. To check out their vast range of products, visit http://www.govindsteel.com.