Why is Lavabo's drainage pipe curved?

If you pay attention, you will see that the lavabo drainage pipe has a curved shape, the first part bends down and then goes upwards, what purpose does it do? Why don't people make it into a straight tube, and save material?

The bent pipe section forms a U-shaped catheter.

In fact, the curved lavabo drainage pipe has a certain effect. The bent pipe section forms a U-shaped catheter.

According to the principle of mutualization , after the water in the lavabo is completely drained, U-shaped tubes still retain a certain amount of water, the water level in the two lumen is equal. As such, it does not affect the drainage, but also prevents the odor phenomenon under the drainage outlet.

If we use a straight tube, after the water has been drained, there will be no stench in the room. In addition it has the effect of eliminating impurities.

In the bend, the pipe can be designed as a connecting pipe or deposition navel, easy to open to clean the pipe clogging impurities. This is also easier than when we want to clean a clogged straight pipe.

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