Trap refers to a kind of fitting with water seal inside the sanitary appliance or on the drainage pipe section of the appliance.

The trap is an accessory that sets a certain height of water column on the drainage pipe of the sanitary appliance or inside the sanitary appliance to prevent the gas in the drainage pipe system from flowing into the room. The water column with a certain height in the trap is called a water seal.

The trap is one of the main accessories of the drainage pipeline in the building. Some sanitary ware structures have traps (such as sitting toilets). When the structures are not connected with the industrial wastewater receiver and the domestic sewage pipeline or other drainage pipelines that may generate harmful gases, the trap must be set below the drainage outlet.

The trap is divided into S-shaped trap, P-shaped trap and U-shaped trap. S and P, u can vividly describe the shape of the trap.

(1) The S-shaped trap is used for the place vertically connected with the horizontal drainage pipe.

(2) The P-shaped trap is used for the place where it is connected with the horizontal right angle of the horizontal drain pipe or the vertical drain pipe.

3) The bottle trap and the trap with ventilation device are generally exposed on the discharge pipe of sanitary appliances such as wash basin or wash basin, and the form is more beautiful.

The water seal of the trap is easy to be damaged due to insufficient water seal depth. In addition, some sanitary appliances lose their water seal function due to long use interval, especially the floor drain, which has no replenishment water for a long time, and the water surface of the water seal is continuously evaporated. This is the main reason for the escape of odor. Therefore, management personnel are required to have common sense in this respect. It is necessary to inject water into the trap of the floor drain regularly to maintain a certain water seal height.