Author:Site Editor Publish Time: 2021-01-30 Origin:Site
In addition to the basic choices in the shape of the manhole cover, there are also certain requirements for the adaptation of the environment. Choosing a suitable manhole cover can solve a lot of unnecessary troubles. In terms of details, we can also strive for perfection.
Common manhole cover damage: aging, missing manhole cover, broken manhole cover.
The existing manhole covers have defects such as noise, skipping covers, and poor sealing, which need to be improved.
Manhole cover quality and design issues, such as frame fracture, inspection manhole settlement. The road around the manhole cover is damaged. The frame and the manhole cover are not matched. The manhole cover rattles, the manhole cover frame is poor, and the collar is separated from the road surface.
The construction process is not standardized. The quality is substandard or aging. The manhole cover is stolen, improperly used, and the manhole cover is not matched.
The airtight manhole cover has a good sealing effect and has a built-in sealing ring. It is one of the commonly used manhole cover choices in communications, power, and other industries. Common ones are rectangle, circle, or square. The air-tight manhole cover is better fixed, not easy to loosen, and not easy to crush. An inner manhole cover can be set under the manhole cover to prevent personnel from falling into the "double insurance". The airplane door design is adopted, the inner edge of the frame has a certain slope, the outer edge of the manhole cover is parallel to it, and the manhole cover is covered, directly embedded, and will not move randomly, and sufficient clearance is reserved for the rubber ring to seal impermeable. The built-in sealing strip is made of rubber, which not only has airtightness but also reduces the noise when the car passing.
Some underground drainage has a foul smell and uses a sealed manhole cover. It should be noted that the size of the manhole cover should be tight to prevent gas leakage. Do not use holes on the surface of the manhole cover. Someone once said that cigarette butts with sparks were thrown into the sewer through the through-hole of the manhole cover, and the sewer was filled with ammonia and other flammable gases, causing irritability. The manhole cover exploded to a height of more than ten meters, which was very dangerous.
When the manhole cover is used in places where a bad smell or water leakage is not desired. The covering layer is used for the sewer pipelines close to the terminal building and used as the tunnel covering layer on the cable duct. The lid is recessed and filled with concrete or any other filling material. The cover is therefore integrated with the surrounding environment and has an aesthetic appearance.
For some environments that require maintenance or have underground protection facilities, small animals and people should be prevented from easily entering and destroying internal items. Therefore, the installation and sealing requirements of the manhole cover are relatively high. For this, hinges and locks can also be installed to prevent others from opening the manhole cover. The material of the manhole cover is ductile iron, which can be used for more than 30 years.
The traditional manhole cover sealing structure is mainly composed of a manhole cover and a frame. The sealing structure only relies on the contact surface of the manhole cover and the frame to play a certain sealing role. If the contact surface is uneven or there are gaps, it will cause Seal failure, the phenomenon of easy accumulation of water in the chamber.
Our air-tight manhole cover and the frame are sealed by a sealing tape, and a locking device is added to make the manhole cover fully contact the sealing strip on the frame to achieve a sealing effect. The elastic variable of rubber is large and the shape is easy to recover. If the manhole cover is opened many times, the sealing effect can still be achieved. In order to solve the problem of poor sealing performance and easy accumulation of water in the chamber in the prior art. A sealing strip is set between the manhole cover and the frame, and a locking device that makes the manhole cover fully in contact with the sealing strip on the frame is added. The locking device includes a lifting ring, a locking piece, a compression spring, a rubber gasket, and the lifting lugs and the bottom of the locking member are provided with a buckle for locking. The lifting ring is connected with the top of the locking member. The locking device makes the manhole cover fully in contact with the sealing strip on the frame, enhancing the sealing effect and effectively The problem of easy accumulation of water in the chamber is prevented.
It also has a double-layer manhole cover. The double-layer manhole cover is a manhole cover composed of upper and lower manhole covers. The upper manhole covers are smaller and lighter, it is covered on the middle hole of the lower manhole cover. A fixed connection ring and corresponding keyhole are arranged between the two manhole covers. When in use, the upper manhole cover can be opened to patrol gas and other public facilities. For wire construction or maintenance, the small cover can be locked when not in use, which is convenient for operation and reduces the labor intensity of the operator. The sub-cover of the double-layer manhole cover is suitable for water supply and drainage ditch, various entrance wellheads of buildings in water supply, and drainage pipeline engineering.
For gas station operators, the manhole cover in the gas station, especially the load-bearing manhole cover under the driveway, is a special manhole cover used in a special environment, and its quality and performance requirements are more stringent. How to choose a manhole cover for gas stations? We have the following suggestions:
Strong bearing capacity: The gas station manhole cover needs to have a strong bearing capacity and high hardness to withstand the rolling of various heavy trucks without breaking, thus effectively avoiding the manhole cover from falling off What happened.
High tightness: Because there is pipeline equipment connected to the oil tank in the operation chamber under the manhole cover, the waterproof manhole cover with good sealing performance can prevent rainwater from entering the manhole and tank mouth area.
Anti-static: The use of anti-static manhole covers in oil and gas environments can prevent discharge and fire accidents caused by friction and other reasons.
Long service life: The manhole cover should be made of corrosion-resistant materials. If the product has the characteristics of abrasion resistance, acid and alkali resistance, aging resistance, and resistance to deformation, the service life can be extended, thereby reducing the operating cost of the operator.
Anti-theft and loss: The loss of the manhole cover not only causes economic losses for the operator, but also the loss of the manhole cover will cause unsafe accidents such as people, vehicles falling, or stuck in the manhole.
During the daily oil measurement, routine inspection, or maintenance of equipment, pipeline connections, leakage, and leakage in the gas station, the manhole cover must be opened and closed. Of course, it also includes the manhole cover/manhole cover. Inspection of the cover seal itself.
This requires the construction personnel to use professional tools and adopt the correct way to open and close the manhole cover; if artificial or unprofessional tools are used to forcibly open and close the manhole cover/manhole cover seal The ring causes the cover frame to be misaligned when closing the cover, and the assembly is not flush, which affects its tightness.
A special opening handle must be used to open and close the manhole cover.
Do not insert any objects between the manhole cover and the frame. Regularly clean the debris in the lifting earholes of the manhole cover.
Grease or antifreeze should be injected into the ear holes in cold winter weather.
When opening and closing the manhole cover, when the manhole cover is closed, the polygonal planes of the manhole cover and the frame must be aligned, and the manhole cover must be pushed into place with your feet.