The specifications for drainage fittings used in home decoration are generally 20 pipes, 25 pipes, and 32 main pipes. Some are divided into hot water pipes and cold water pipes. The accessories include equal diameter elbows, equal diameter tees, external connections, reducing tees, reducing elbows, internal tooth elbows, external tooth elbows, and other different specifications ( nono521521)

Drainage pipes are mainly responsible for the drainage of rainwater, sewage, and farmland irrigation. Drainage pipes are divided into concrete pipes (CP) and reinforced concrete pipes (RCP).

The specifications of drainage pipes include inner diameter DO (100mm -3000mm), length LO (1m -20m), pressure index, Class I, Class II, and Class III caliber, which are divided into flat mouth, tongue and groove, socket, double socket, and steel socket.

The general specifications of household water pipes include: DN15 (4 pipes), DN20 (6 pipes), DN25 (1 inch pipe), DN32 (1 inch 2 pipes), DN40 (1 and a half inches pipe), DN50 (2 inches pipe), DN65 (2 and a half inches pipe), DN80 (3 inches pipe), DN100 (4 inches pipe), DN125 (5 inches pipe), DN150 (6 inches pipe), DN200 (8 inches pipe), DN250 (10 inches pipe), etc.

The meaning of a water pipe with a diameter of 25 × 1/2 is that its outer diameter is 25. The actual corresponding nominal diameter is DN20 (commonly known as 6 tubes). You can buy a 6-point faucet. You can also buy a 4-point faucet (just add a variable diameter between the pipe and the faucet).

The styles and materials of household faucets vary greatly, but the threaded parts connected to the pipes are classified according to sizes such as 4 inches, 6 inches, and 1 inch. Don't worry about buying the wrong one.

The commonly referred to 4-branch pipe is measured in inches, so 4-branch pipe is 1/2 inch (4/8=1/2), and one inch=25.4mm. Therefore, the inner diameter of 4-branch pipe is 25.4/2=12.7mm, which is commonly referred to as the inner diameter of DN15 water pipe.