How to Choose the Correct Replacement Manhole Cover: A Detailed Guide

Manholes are undoubtedly one of the most important civic amenities. From facilitating access to maintaining public spaces and underground drainage systems, manholes play an important role in ensuring civic health and safety. And that is why they are spotted across all municipal and city neighbourhoods. However, the best manhole cover manufacturers in India recommend replacing them from time to time.

Why Should Manhole Covers be Replaced?

Manhole covers have defined or undefined lifespans – similar to all other manufactured product counterparts. Since they are exposed to varying strengths of pressure, force, as well as environmental elements, replacing them periodically, is ideal. Besides, other physical damage like a dent, a fracture, a broken lid, protruding or misfitting lid – are a few other reasons existing manhole covers must be altered with new ones. Leading manhole cover suppliers suggest replacement as the best practice to minimise and avoid any compromise with the safety of pedestrians and vehicles.

Things to Consider Before Replacing Manhole Covers

Replacement of manhole covers may seem easy but there are several factors to consider. Below are some of the prominent factors to consider before changing a manhole cover. 

• Accurate measurements of the existing cover

One of the first things to do before choosing a new cover for a manhole is to measure the previous one. Because not all manholes are the same, a range of manhole covers is made available by manufacturers in India. It is important to know if the cover or the entire frame has to be replaced. If the complete frame does not need to be replaced, it is important to measure the manhole cover size alone. 

Accurate measurements of the clear opening size and the frame size are crucial for a perfect fit of the new cover for the manhole. For manholes with inspection chambers, the apt cover size can be measured by knowing the diameter of the chamber. Ideally, both the cover and frame should be changed together to make the best fit. 

• The loading weight of the manhole cover 

Oftentimes, the wrong weight loading is among the main reasons for the damage caused to a manhole cover. If the previous cover was damaged due to the weight load, the replacement must be better. Note the previous loading of the cover and upgrade it by a notch. Look for covers that are listed higher on the load rating chart. For example, if the previous cover had a load rating of C250, it is ideal to upgrade to the next rating on the chart. It is important to remember that the volume, as well as the speed of traffic, should also be kept in mind while choosing new manhole covers. 

• The material appropriate for the location

The material of the manhole cover is essential in ensuring its purpose, efficacy, and durability. While a low-traffic area can function with a steel cover, a highway requires a heavy-duty and sturdy cover counterpart. 

Best manhole cover manufacturers in India offer several variations of materials for manhole covers – cast iron, ductile iron, steel, and polypropylene covers are some of the most prominent ones. These covers suit different locations and requirements depending upon the requirement. 

Heavy-duty covers are ideal for industrial, airport, and docks where they have to withstand high weight loads and extreme pressures. Lightweight covers such as the ones made from composite materials, plastic, and steel are ideal for less crowded neighbourhoods or residential purposes. 

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• The type of cover surface suitable

Manhole covers are not only available in plain, round, or square shapes. Based on the existing cover, the choice of design, shape, and even the type of cover surface, come into play. Leading manhole cover suppliers cater to more than the solid top covers– recessed as well as custom designs to provide according to tailor-made requirements. 

Further, the surface covers also add to the aesthetic and functional aspect of the manhole covers. Recessed covers are preferred for gardens, decorative pathways, and spaces where visual coherence is essential. Best manhole cover manufacturers in India have always seen a steady demand for recessed manhole covers for their ‘less noticeable’ or ‘masquerading’ characteristics. 

• The kind of sealing/locking mechanism

Since manholes are concerned with public safety or keeping elements from entering a particular passage, the right fit is always not enough. They must be sealed or locked the right way to avoid legal and environmental consequences. While several manhole covers need to be closed off with sealants, many manufacturers today have locking systems. 

These locking systems not only seal the covers to the frame but also aid in avoiding cover thefts– which are common in many parts of the world. Depending on the location, application as well as the cause of the replacement, the locking system can be selected. 

Crescent Foundry, one of the manhole cover manufacturers in, offers a wide range of customised manhole covers, suitable for cover replacements and new installations. As pioneers in the industry, the company also offers other municipal, automotive and agricultural solutions.