In home improvement and engineering drainage systems, PVC-U drain pipes are absolute "old acquaintances" - they are corrosion-resistant, light in weight, have little drainage resistance, and are affordable. They have contracted almost all drainage scenarios, from bathroom floor drains to community main pipes. But in the face of different calibers of pipes on the market, many people will be confused: what is the difference between 50mm and 75mm pipes? Can 110mm be used instead of 160mm? Today we will "dismantle" the specification table of PVC-U drain pipes, and explain in the most straightforward way the parameters of each caliber and where to use it.

first briefly describes the core advantages of the PVC-U drain pipe: it is not afraid of grease in domestic sewage and impurities in rainwater corrosion, nor will it rust and age like a metal pipe; the inner wall is smooth like a mirror surface, and the water flow resistance is small when draining, even if the water flow is large, it is not easy to block; installation is more worry-free. As long as the socket connection is coated with special glue and the pipe is inserted, the novice can learn it from the master. These advantages make it the "main force" of the drainage system.

Next comes the key point - what are the differences in parameters and applicable scenarios of different calibers of PVC-U drain pipes? Let's pick the most common 5 calibers:

The first one is 50mm caliber. Its outer diameter is generally 50mm, the wall thickness is usually 2.0mm (there are also 1.8mm lightweight models), and the length is mostly 4 or 6 meters. This caliber pipe is suitable for "small flow" scenarios: such as the floor drain of the washing machine on the balcony, the spare floor drain next to the bathroom sink, or the drain branch pipe of the small bathroom cabinet. For example, your balcony has a washing machine floor drain, and the 50mm pipe is just right - the flow is enough to drain the wastewater of the washing machine, and the pipe will not take up space on the balcony because it is too thick.

The second one is 75mm caliber. The outer diameter is 75mm, the wall thickness is about 2.3mm, and the length is also 4 meters or 6 meters. It is a circle thicker than 50mm, suitable for "medium flow" scenarios: such as the drainage of the kitchen sink (the daily discharge of vegetable water, as well as vegetable leaves, oil stains and other sundries), the main drainage of the bathroom cabinet (the water for washing face and brushing teeth is summarized here), or the secondary drain pipe of the guest bathroom. The 75mm pipe for the kitchen sink is very suitable, because the drain of the sink generally matches this diameter, and the slightly thicker pipe is not easy to be blocked by vegetable leaves.

The third one is 110mm caliber, which is the most commonly used "large diameter" in home improvement. It has an outer diameter of 110mm, a wall thickness of 3.2mm (the engineering may be as thick as 3.5mm), and a length of 4 meters or 6 meters. The pipe of this caliber is "exclusive to the toilet" - the toilet drain in the bathroom must be 110mm, because the toilet has a large displacement, and occasionally there are sundries such as toilet paper, the small-caliber pipe cannot bear it at all, and it is easy to block the water. In addition, it can also be used as the main drain pipe for home improvement (such as aggregating the water from the bathroom and balcony into a pipe), or the combined drainage of the balcony washing machine + floor drain.

The fourth one is 160mm diameter, which belongs to the "engineering grade" little brother. The outer diameter is 160mm, the wall thickness is about 4.0mm, and the length is mostly 6 meters (the engineering one will be longer). It is suitable for "building-level" drainage: such as the main drainage riser in the kitchen of the entire building (to aggregate the water in the kitchen on each floor), the drainage branch pipe in the community (connecting the building to the main pipe), or the main pipe in the bathroom of the shopping mall. For example, a 30-story building has a kitchen on each floor, and all the kitchen water must be drained to the main pipe of the community through 160mm pipes. If you use a small diameter, you will definitely reverse water due to too much flow.

The last one is 200mm caliber, which is the largest in the common specification. The outer diameter is 200mm, the wall thickness is 5.0mm, and the length is 6 meters or more. It is the main pipe of the "community level" - for example, the sewage of the entire community is discharged through it to the municipal pipe network, or the drainage system in the basement (the water flow in the basement is high and it has to bear the pressure of the ground). The main drain pipe of a large shopping mall will also use this caliber. The wall thickness of this pipe is very thick, and it is highly resistant to pressure. Even if it is buried in the ground, it will not be fracked.

After talking about the specifications and scenarios, I will give you a few shopping tips: First, look at the uniformity of wall thickness - touch the pipe with your hands, if some places are thin and some places are thick, don't buy it, it is easy to crack; second, look at the surface - the surface of the pipe should be smooth, without cracks or spots, so that the inner wall will not hang dirt and not be easy to block; third, ask about the length - generally 4 meters or 6 meters, according to the construction needs of your home, to avoid buying too long and wasteful; fourth, be sure to choose pipes that meet national standards, such as wall thickness up to standard and pure material, otherwise it will leak after three or five years, and it will be more troublesome to renovate at that time.

In fact, the selection logic of PVC-U drain pipe is very simple: the larger the diameter, the more water can be discharged, and the more "core" the corresponding scene. Remember these corresponding relationships - 50mm small floor drain, 75mm kitchen sink, 110mm toilet, 160mm building branch pipe, 200mm community supervisor, you can basically handle 90% of the drainage needs. Next time you go to the building materials market to choose pipes, you don't have to be in a daze at the specification table!

To sum up, the specification table of PVC-U drain pipe is actually "flow matching table" - different calibers correspond to different water consumption. If you choose the right caliber, the drainage system can be "smooth and smooth". Whether it is home improvement or engineering, first think about "where to use", and then look at the corresponding diameter parameters, you can choose the right pipe.