Is the second floor of a high-rise building repaired after 2o2o easy to return to water?

The second floor of the high-rise building repaired after 2o2o basically does not return water. Because the construction technology is becoming more and more mature, developers want to sell the house, so it is natural to improve the quality. Now there are independent backwaters and check valves below the third floor, so there is no problem.

Backwater, that is, backwater elbow, also known as trap, refers to a pipe fitting with water seal inside sanitary ware or on the drainage pipe section of the appliance.

There will be a certain amount of water in the trap, which can isolate the air under the sewer and prevent the odor from entering the room. Traps can be divided into S trap and P trap, and S and P can vividly explain the shape of traps.

The working principle of the trap is to use a horizontal S-shaped bend to produce a water seal to prevent the odor of the sewer from flowing back.