In the building water supply and drainage system, PVC drain pipe is a veritable "invisible hero" - it is corrosion-resistant, light weight, and even the decorator loves its ease of installation. But in the face of a string of caliber numbers from 50 to 500, many people have made difficulties: How big should the wash basin be? Choose 110 or larger for toilet drainage? What is the importance of large-caliber pipes for municipal engineering? Today we will straighten these question marks, from the smallest 50 caliber to the largest 500 caliber, and explain the "details" of each specification one by one.

First, let's talk about the most common 50-caliber PVC pipe. Its outer diameter is generally 50mm, the wall thickness is about 2.0-2 mm, and the nominal pressure is mostly 0.63MPa. Nine times out of ten, it is the drain pipe of your bathroom wash basin and balcony mop pool. Don't look at the small diameter, the effect is not small - when connecting these small water sanitary ware, as long as the seal is done well (with PVC rubber ring or glue), it will basically not leak; but be careful not to pour hair and residue into it, it is easy to block.

is next to 75 caliber, with an outer diameter of 75mm and a wall thickness of 2.2-2. The drainage of the kitchen sink and shower room depends on it. Compared with the 50 caliber, its "belly" is a circle larger, suitable for scenes with slightly larger displacement - such as the water for washing dishes in the kitchen and the bath water in the shower room. The flow is larger than that of the wash basin, and it can be "caught" with 75 pipes. Remember to leave the slope (generally 1% to 3%) when installing, otherwise the water will not be drained cleanly, and there will be peculiar smell after a long time.

is 110 caliber, which is the "main domestic drainage force". The outer diameter is 110mm, the wall thickness is 3.2-3 mm, and the nominal pressure can reach 0.63-1 MPa. It must be used for toilet drainage and indoor main drain pipe (such as the one that leads from the bathroom to the downstairs). Why? Because toilet flushing is an instantaneous large flow, the wall thickness and inner diameter of 110 pipes can just withstand the impact; special attention should be paid to the turning when installing - use a water elbow (not a 90-degree right angle), which can reduce the resistance of water flow and is not easy to block.

160 caliber enters the category of "medium-sized pipes", with an outer diameter of 160mm and a wall thickness of 4.0-4. Have you ever seen a vertical main drain pipe in a multi-story building? For example, the drainage main pipe of each floor in the community, or the main pipe of the bathroom of the small shopping mall, most of them are it. This caliber pipe must be fixed firmly, after all, it has to carry the drainage of the whole building. If it is not fixed properly, the water flow will shake, and the interface will be easy to loosen after a long time.

200 caliber began to be biased towards municipal and public areas, with an outer diameter of 200mm, a wall thickness of 5.0-5, and a nominal pressure of 0.8-1 MPa. It is commonly used for drainage in underground garages and storm pipes in municipal branch roads. This kind of scene has a larger displacement and is buried underground, so the thickness of the pipe wall is higher - it has to withstand the pressure of the ground and prevent acid and alkali corrosion in the soil.

and then up are 250, 315, 400, 500 these large diameter pipes, mainly used in municipal main road drainage, industrial park rainwater drainage, or large commercial complex outdoor drainage. For example, 250 caliber outer diameter 250mm, wall thickness 6.0-7; 315 wall thickness 7.0-8 mm; 400 wall thickness 8.5-9 mm; to 500 caliber, wall thickness to 10.0-11 mm. These pipes are not laid casually - in municipal engineering, concrete foundation must be made first to prevent ground settlement and crushing the pipe; ring stiffness must also meet the standard (generally 4kN/m 2), otherwise it will not be able to withstand vehicle rolling.

Finally, I want to say the truth: choose PVC drain pipe, don't just look at the diameter, you have to combine "scene + water volume + pressure". For example, choose 110 pipes for the toilet at home. If it is selected as 75, the water may overflow once flushed; use 500 pipes for the main road of municipal government. If it is selected as small, water will accumulate in rainy days. There is also wall thickness. Don't be greedy for cheap and buy thin ones - for example, 110 pipes have a wall thickness of less than 3mm and are used in the main drainage pipe. It is easy to crack after a long time.

In fact, the specifications of PVC pipes are not so complicated. Remember the logic of "small diameter corresponds to small water volume, and large diameter carries large flow". If you compare the parameters of this article, you can basically choose the right one. Next time you encounter decoration or engineering selection, you can also be half a "knowledgeable person"

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