Description
Wells on the surface of roads and streets have been a mystery to most of us as children. Many of us were afraid of falling into these wells and others were curious to see the world below them. These well, which are called manhole or adam-ro, according to their use, different types of pipes and fittings such as electric pipes, gas pipes or even copper pipes with copper pipe insulation have passed through them and are usually covered with cast iron manhole covers. Manholes are made with different materials such as polyethylene manholes in order to access underground water, gas and electricity pipes and to repair, maintain and handle them in different places. The surface of these wells is covered with strong and resistant valves called manhole covers, which have different types, and one of them is the cast iron manhole cover.In this article, we intend to introduce manhole covers in cast iron, brick, concrete, composite and polyethylene manhole covers along with their efficiency and advantages over other types of manhole covers.
What is a manhole cover?
At the level of alleys and street, there are relatively large openings under which there are an inter connected network through which underground facilities such as water, electricity and gas pipe are distributed throughout the city. Water, gas or electrical technicians enter underground channels through manhole to address underground utility problems and repair and inspect connection. The entrance of these channels on the level of cities and streets is covered with a valve and a special frame mode of cast iron, concrete etc.; which are called manhole cover.
Manhole cover types
Manhole cover have different type in terms of size material, etc. the most common classification of manhole cover is based on their material, for example, cast iron valve. Manhole has different characteristics in each type for example, the weight bearing and strength of manhole cover is even effective in their pricing. In the following, we will introduce some common and widely used types of manhole covers.
Concrete manhole cover
One of the oldest types of manhole cover is the concrete manhole cover. This valve is made using concrete ad has relatively high resistance. Concrete manhole covers are resistant to heat and impact and have a long service life, but they do not have proper tensile strength, Also the price of this type of manhole cover. These valve are easily designed manufactured, installed and implemented create a uniform surface after being placed in the entrance of the well. As mentioned, concrete manhole covers has good resistance, but compared to cast iron manhole covers, this resistance is less and over time they break and crumble, so they have given their place o cast iron valve.
Cast iron valve
The most widely used type of manhole cover is cast iron valve. This valve is among relatively heavy valve that cannot be moved easily. Cast iron manhole cover can be recycled and incase of damage or breakage, they can be melted and used again during the production of a new cast iron valve. The resistance of the cast iron manhole cover is suitable for impact but it is less sensitive to moisture and rust. Also the efficiency of the manhole cover (cast iron valve) is more than other valves due to the appropriate weight. The cast iron manhole cover is not so heavy that it I impossible to remora them, it is so light that it is lifted from its place when the cars pass. Also due to the increase in the price of metals, cast iron valves have attracted the attention of thieves and we witness the theft of cast iron valves every day, so they are considered anti-theft type of iron valves.
Composite manhole cover
Another type of manhole cover is the composite valve, which is 70% lighter than the cast iron and concrete manhole cover. This valve is non-recyclable and due to its weight, it is possible to move it a lot, but it is one of the best in other features such as resistance to acidic substances, acidic substances etc.
Polyethylene manhole cover
Polyethylene manhole cover is famous as another type of valves due its low weight and long services life. This manhole cover is made of the same polyethylene pipe and carrugate pipe. The polyethylene manhole cover its self has different types, including the double-walled polyethylene manhole cover one of the disadvantages of such valves is that they lift up wen cars pass so their use is possible only with a special lock and the use of cast iron manhole cover is more common in places where cars pass. Also, due to higher resistance, cast iron manhole cover is more useful for place with heavy traffic load.
Use of manhole cover (cast valve) and its place of use
As the mentioned, manhole covers of any kind are used to cover the entrance of the most widely used of which is the cast iron valve the advantages and applications of using a cast iron manhole cover are many, the most important of which are:
- Covering the opening of manholes and wells in order to pass through them more easily.
- Durable and suitable material.
- Preventing rain from falling on underground connections and causing problems such as their decay.
- Directing rainwater to urban sewage systems in the streets in order to prevent water accumulation in the city.
- Use as the main valve of all kinds of facilities and etc.
Advantages of using cast iron manhole cover
As mentioned the application and benefits of using the cast iron manhole cover are many in the previous section, we reviewed some of the application of this valve, and here we intend to introduce some of the advantages of the cast iron valve, which are:
- Not harming the environment and being recyclable
- Creating a smooth surface for passages and not having bumps
- Suitable weight and relatively easy portability
- Resistance to impact, heat and sunlight
- High safety during installation
- Easy to run
- The ability to install a valve to become an anti-theft valve
- The ability to engrave a logo, logo or number on them and etc.
Introducing the dimensions of the manhole cover (cast iron valve)
Cast iron manhole covers are produced in different dimensions and in square, rectangular and circular shapes. These valves can be produced even at the request of employers in custom dimensions and sizes. Some of the standard dimensions of the standard dimensions of cast iron valves in any geometric shape are:
- Diameter 26, 32.5, 60-100 cm in circular valves
- Dimensions 60*80, 60*100, 60*120 and… in rectangular valves
- Dimensions of 40×40, 60×60, 80 and 100 cm in square valves
What is anti-theft manhole cover?
One of the important problems of manhole covers and especially cast iron valves is the possibility of their theft. Except for concrete valves that valve has a high weight and cannot be recycled other valves face the possibility of theft; for this reason, during their installation, an especially lock or valve is used to reduce the possibility of theft. Another anti-theft solution for this cast iron manhole cover is to install a chain under the valve and connect it to the ground and connection
Conclusion
By buying manhole covers and using them at the entrance of wells, the safety of the passages can be increased the only thing that should be taken in to account when buying this product is it resistance, efficiency and cost-effectiveness in terms of usage. In this article, we introduce cation manhole cover and found that one of the most efficient types of manhole covers in cast iron valve.
