Manholes are the commonly used maintenance utility underground structures to provide access to installed pipelines for inspection and cleanout. It is a vital component of the water supply and sanitary system, the basic underground utilities. Manholes are frequently spotted on the streets and paved paths. Manhole covers are lids covering the open manholes from people tripping into them or preventing unauthorized personnel from entering. We may walk over them every day, yet we don’t still stop to think about how vital these manhole covers can be in our day to day life. Indian manhole cover manufactures are well-known world- widely for their renowned quality products. According to a survey report, most of the US manhole covers are imported from India. Make in India initiative policy has enhanced the manufactures to attain new heights. In some countries, like Japan, manhole covers have become an outlet for people to showcase their artistic skills, where we can find colorful manhole covers everywhere.

Manholes And Their Importance

Manholes are commonly used for connecting two or more pipes for water supply or sanitary sewer lines. Modern-day drainages are full of pipes and tunnels that pass beneath the roads and pavements all over cities and towns. Each application requires different diameters and entrances of the manhole at various angles and elevations. A manhole cover is an essential requirement to cover these passages with a removable plate adequately. Manholes are mainly used for maintenance work. Manhole covers will prevent anything or any person from falling in and also will keep unauthorized people out. Manhole covers may look as if a simple piece of plate or lid covers large holes, but there are many designs and techniques involved in producing these products. Manhole cover manufacturers adapt to current trends and create manhole covers with sophisticated technology advancements. They strive to meet the demands of the consumers, as each purpose of applications differs. Leading manufacturers of manhole covers recommend replacing them after certain intervals — to ensure uncompromised safety of traffic or pedestrian movement.

Manholes Types

There are three types of manholes they are normal, shallow, and deep. Every kind of manhole is chosen for different applications depending upon the function they need to serve and the sewer or drainage water line size. Manholes can be produced using a variety of materials comprising of precast concrete, fiberglass, and plastic.

Normal Manholes

These types of manholes are about five feet deep or 150 centimeters. They are usually found in the sewage or drainage water line, with a hard lid as a cover on top. They typically are available in square or rectangular in shape.

Shallow Manholes

These types of manholes are about two to three feet or 75-90 centimeters of shallow depth. They are normally placed at the starting of a sewer or drainage water conduit passage and in the areas that are not subjected to heavy traffic. These types are suitable for maintenance work and are also known as inspection chambers with a light lid as a cover at its end.

Deep manholes

Any manholes deeper than 150 centimeters and fitted with a thick lid as a cover on the top are considered deep manholes. These manholes are always incorporated with a heavy manhole cover and a built-in ladder to ease the personnel’s entry and exit if required.

Manhole Covers Types

Manhole covers are a removable cover that serves as a lid to close the manholes. Traditionally, manhole covers were made of cast iron, concrete, or even a combination of the two. These materials are preferred due to specific qualities like durability, inexpensive, and heavy enough to stay in place. However, technology has led to various alternative manhole cover materials like composite, fiberglass, and plastic.

Keep Reading: Types Of Cast Iron Inspection Covers & Their Applications

Ductile Iron

These manhole covers are primarily made of ductile iron (SG iron) or nodular iron a unique form of iron. Depending on the nodularity, the quality of the iron is determined whether it is good or bad. Ductile iron covers are known for their solidness, strength, heavy-duty, and resilient features. Ductile iron will not corrode as quickly as cast iron, as the manhole cover manufactures spray anti-rust asphalt paint at the surface of the covers. The loading classes for ductile iron manhole covers are subjected to BS EN 124:2015 guidelines and are predominantly used over a D400 class.

Recessed

These types of manhole covers are installed in recessed areas suitable for laying block paving, cement, and a layer of screed for aesthetic finishes in pedestrian pathways. There are various features and applications of Recessed manhole covers and it is considered the right solution for internal manhole covers in hospitals, cast iron manufacturing workshops, and residential areas for apartments and domestic gardens. The loading classes for recessed covers are subjected to FACTA regulations.

Solid Top

These types of manhole covers are designed to be prominently visible on the floor. A solid top silver manhole cover is made of lighter galvanized steel with an anti-slip surface. These are usually installed in areas where regular maintenance and safety inspections are often conducted. Solid top covers are preferred for lighter usage, fitting flush at ground level, and inset grab handles. Solid top covers loading classes are subjected to BS EN 124:2015 guidelines. Manhole cover exporters adhere to the regulations of the loading classes to meet the international standards.

Applications

Manholes will provide a safe passage to the sewage conduits, which need to be opened now and then for maintenance and emergency purposes. Manhole covers protect the roads from being flooded during monsoons by preventing the water from getting accumulated. It serves a crucial purpose because, during monsoons, the accumulated water will make the roads slippery, causing inconvenience for the people to walk or ride a vehicle. Manhole covers protect people and animals from falling into the holes accidentally. They prevent unpleasant smells and harmful gases from coming out of the sewage tunnels, which could pose a massive threat to people’s lives. Manhole cover manufacturers are making sure that the products are made heavy not to be stolen easily and be cost-effective for clients in avoiding thefts. Despite heaviness, manhole covers are designed with magnetic technology by allowing them to be lifted with ease, with the help of cranes rather than manually. Each area requires different types of manholes covers varying upon the functions they serve. Determining the right choice of manhole covers is important as it affects the efficiency and effectiveness of the manhole covers. Recessed type covers are used for residential projects and service industry projects like hospitals, hotels, malls, etc. Ductile iron covers are used for airports, docks, roads, and pedestrian walkways as they require a span of long lifetime and agility to overcome heavy vehicles. Solid top covers are preferred in industrial areas and heavy-duty manufacturing workshops. Manhole cover exporters offer a wide variety of manhole covers in different sizes, strengths, and loading capacity to cater to the customers’ demands globally.

In our day to day life, we may have walked over these manholes numerous times, but we would not have understood their importance. Indian foundries have made a name for themselves in the global market through these manhole covers. Manhole cover manufacturers and exporters strive to adhere to the regulations and innovative designs to meet international standards. These factors have placed India as a global leader in exporting manhole covers.