How to open the manhole cover with lock?

Find a hard hook to hang in the small hole and pull it up and come out.

Well covers are used to cover roads or deep wells at home to prevent people or things from falling. According to the material, it can be divided into metal manhole cover, high-strength fiber cement concrete manhole cover and resin manhole cover. Generally use a circle. Can be used in green belts, sidewalks, motor vehicles, docks, alleys and so on.

From 2065438 to March 2009, the manhole cover monitoring system independently developed by No.203 Institute of Aerospace Science and Technology came out.

Performance characteristics:

1, high strength: magnesite test, high compressive strength, bending strength and impact strength, and good toughness. After long-term use, the manhole cover will not be crushed and damaged, and the "urban black hole" accident can be completely eliminated.

2. Beauty: the surface pattern of magnesite manhole cover is beautifully designed, with bright and adjustable colors, beautifying the urban environment.

3. Easy to use and light in weight: the weight of the product is only about one third of that of cast iron, which is convenient for transportation, installation and emergency repair, and greatly reduces the labor intensity.

4, anti-theft: magnesite manhole cover has no recycling value and is naturally anti-theft; According to the needs of customers, it is equipped with a locking structure to realize the anti-theft of property in the well.

5. Strong weatherability: Through scientific formula, advanced technology and perfect technical equipment, the magnesite manhole cover can be used normally at -50℃ ~+300℃.