When renovating water, electricity and municipal pipe networks, many people will wonder: what is the difference between water supply pipes and drain pipes, which are also PVC pipes? Obviously it looks similar, why is the price and use so different? Today, let's break down the difference between the two from the core three dimensions.

Let's talk about the pressure level first - this is the most intuitive difference. The job of the water supply pipe is to "deliver water", which has to withstand the pressure of the water supply system (such as the pressure of the water plant, the secondary water supply of the high-rise residential), so the pressure level must be high. The common PVC water supply pipe pressure level is between PN1.0 and PN1.6MPa (for example, PN1.6 can withstand the pressure of 16kg), and the high-rise residential will even use PN2.0MPa. The drain pipe is "drainage", relying on gravity flow (water flows down by itself), almost no need to withstand water pressure, the pressure level is usually below PN0.6MPa, and some even only need to bear the impact of the pipe's own weight and water flow. Simply put: the water supply pipe is a "pressure-resistant player", and the drain pipe is a "gravity player".

Look at the material itself - the water supply pipe needs to be "connected to drinking water", so the material must be "hygienic". It uses sanitary grade PVC resin, additives must also be non-toxic (such as calcium and zinc stabilizers), and the production process must meet the drinking water contact standards to avoid the precipitation of harmful substances. The drain pipe does not touch the drinking water, and focuses more on "durability": the material may be made of non-sanitary PVC resin, and even some recycled materials are added (as long as the strength is enough). Additives are also more concerned about impact resistance and anti-aging (such as lead salt stabilizers, but now they are gradually replaced with environmentally friendly ones). In a word: the water supply pipe is a "food-grade player", and the drain pipe is a "practical player".

Finally, there is the use scenario - the "work content" of the two is completely different. The water supply pipe is responsible for delivering "clean water": for example, the water supply pipe in the household, the municipal water supply pipe in the community, the drinking water pipe in the office building, and even the safe drinking water project in the countryside. Drain pipes are responsible for transporting "dirty water/wastewater": such as toilet drainage in the bathroom, vegetable washing water pipes in the kitchen, rain pipes in the balcony, and municipal rain pipe networks and sewage pipe networks. These places use drain pipes. For example: the "tap water pipe" running in the wall of your house is a PVC water supply pipe, and the "sewer pipe" that leads to the downstairs of the toilet is a PVC drain pipe.

In fact, it is very simple to distinguish between the two: first look at "whether to bear pressure" - choose the water supply pipe to send water under pressure, and choose the drain pipe for gravity flow; then look at "what kind of water is going" - drinking water/clean water choose the water supply pipe, sewage/rainwater choose the drain pipe; finally look at the "scene demand" - household water supply pipe, municipal water supply pipe, kitchen bathroom drainage, municipal rain sewage pipe.

Don't confuse the two anymore. Choose the right pipe to ensure the safety of water supply, smooth drainage, and avoid the trouble of rework later. After all, the water pipe is a "hidden project", and it is easy to choose the right one step at a time.