Tap water pipes include steel pipes, PPR pipes, aluminum-plastic pipes, thin-walled stainless steel pipes, new plastic pipes and galvanized iron pipes.
New plastic pipes include rigid polyvinyl chloride (UPVC) pipes, chlorinated polyvinyl chloride (CPVC) pipes, polyethylene (PE) pipes, cross-linked polyethylene pipes and polypropylene (PP-R) pipes.
Specification and size of water pipes for domestic tap water housekeepers: General domestic water pipes are: DN 15(4 pipes), DN20(6 pipes), DN25( 1 inch pipe), DN32( 1 inch 2 pipe) and DN40( 1 inch half pipe). DN 125(5-inch pipe), DN 150(6-inch pipe), DN200(8-inch pipe), DN250( 10-inch pipe), etc.
The water pipe φ25× 1/2 indicates that its outer diameter is 25. The actual corresponding nominal diameter is DN20 (that is, people often say 6 branches).
You can buy a 6 o'clock faucet or a 4 o'clock faucet (just add a reducer between the pipe and the faucet).
Generally speaking, the measuring unit of four branches is inches, so four branches are 1/2 inches (4/8= 1/2), and one inch is equal to 25.4mm, so the inner diameter of four branches is 25.4/2 equal to 12.7mm, which is commonly known as DN/kloc.
Point 4 is the name of the British pipeline diameter and length, that is, 1/2 inches. Equal to15mm in metric system.
1 inch equals 8 points, metric system is 25.4 mm, 6 points equals 3/4 inch equals 20 mm, and 4 points equals 1/2 inch equals 15 mm.
In addition, remember that pipes are all calculated by inner diameter, but the threads of pipes are calculated by middle diameter, which is represented by diameter DN. Threads are divided into metric M and English G, and pipeline threads are generally English, with thread angle of 55 degrees and metric 60 degrees.