What does the combination of specifications and models of manhole cover mean?

Specification and model: diameter * pressure, which is an important symbol for selecting manhole covers.

Compounding: In 2009, the state issued inspection GB/T23858-2009, which defined the composite manhole cover as a kind of manhole cover, and explained its characteristics: the manhole cover was compounded by a certain process with polymer as matrix material, reinforcing material and filler. The new national standard has improved the load requirements of manhole covers, which is in line with the international standard EN 124.

Extended data:

Management technology of manhole cover

1, anti-theft

In order to realize the effective utilization of waste resources, Japan has promulgated a series of laws and regulations, such as the Law on the Promotion of the Utilization of Renewable Resources and the Law on the Disposal of Waste, which stipulate that consumers have the obligation to seal the waste and discharge it in a classified way, and shall not throw it away illegally, and pay the fees according to the regulations.

Therefore, from a legal point of view, the Japanese can not only benefit from handing over scrap metal to recycling enterprises, but also need to pay treatment fees to recycling enterprises. If thieves want to steal the manhole cover, they can only find illegal metal recyclers, and these illegal metal recyclers are often the key targets of the Japanese police.

2. Difference

In Japan, most manhole covers have unique numbers and will be included in the sewer management system.

Taking Tokyo as an example, the Tokyo Sewerage Bureau gives each manhole cover a unique number, which consists of the manhole cover type, the manhole cover identification code and the manhole cover construction date. On the one hand, it can quickly identify the damaged manhole cover, on the other hand, it can know when the manhole cover expires and should be repaired and replaced. Most manhole covers in Japan are maintained by private public utilities.

In addition, the pattern design and shape of Japanese manhole covers also vary from region to region and from department to department. The sewers managed by the municipal, district and town governments are distinguished by the city flowers, district flowers and town flowers on the manhole cover. If the manhole cover is damaged and needs maintenance, the responsible subject can be identified immediately.

Individual-owned sewers will be marked with the word "private" and the owner's surname on the manhole cover to show the difference. The manhole covers of fire hydrants are mostly rectangular or engraved with cartoon patterns of firefighters.

Japan is a country with frequent natural disasters, and there are "emergency shelters" near residential areas. The manhole covers around some shelters are painted in color in addition to indicating the direction with arrows. The yellow arrow means within 200 meters from the shelter, and the red arrow means within 100 meters.

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