When many people decorate and buy PVC drainage pipes, they always put "low price" as the first choice, but ignore a key indicator - wall thickness. Pipes that are too thin are like "paper paste". If the water pressure is slightly large, they may crack, and heavy objects will deform when pressed. It will leak in three or five years. If it is repaired, it will be necessary to smash the wall and replace the pipe, which is expensive and troublesome. In fact, you don't need to find a professional organization. You can take a few daily tools by yourself, measure the wall thickness in 5 minutes, and quickly pull out the "slimming pipe". Today, I will teach you the super practical self-test method.

The most accurate tool: Vernier caliper (also used by beginners)

Vernier caliper is an "artifact" for measuring wall thickness. You can buy one for more than ten dollars, which is highly accurate The steps are super simple: first gently close the two claws of the caliper to see if the 0 scale on the vernier is aligned with the 0 scale of the main ruler - if it is not aligned, just screw the small screw on the side to zero. Then pick one end of the pipe (choose the original end that has not been cut to be more accurate), gently jam the claws on the pipe wall (don't use too much force, it will be deformed), then look at the integer scale on the main ruler (such as the position of the main ruler to 2mm), and then find the scale on the vernier that is aligned with the main ruler (for example, the third line of the vernier is aligned, which is 0.3mm), which adds up to the wall thickness (2 + 0.3 = 2.3mm). Remember to measure a few more points - the middle and both ends of the tube body should be measured to prevent bad merchants from doing the trick of "thick at both ends and thin in the middle".

Emergency method: The tape measure calculates the wall thickness (rough but easy to use)

If you don't bring a vernier caliper, you can make do with a tape measure, which is two steps. The first step is to measure the circumference: use a tape measure to circle the pipe and write down the value (for example, 110mm pipe, the circumference is about 345mm). The second step is to calculate the outer diameter: the circumference is divided by π (about 3.14), such as 3 45 ÷ 3.14110mm (this is the standard outer diameter). The third step is to calculate the wall thickness: if the pipe is a "standard pipe", the inner diameter = outer diameter -2 wall thickness - for example, the standard wall thickness of DN110 is 3.2mm, then the inner diameter is 110-23.2 = 103.6mm. If you can measure the inner diameter (for example, put a tape measure into the tube), just use (outer diameter - inner diameter) ÷ 2. However, this method has a large error and is suitable for emergency comparison.

The fastest way: the coin becomes a "measuring ruler" in seconds

Usually when visiting the building materials market, just pack a one-dollar coin in your pocket - the thickness of the one-dollar coin is about 1.85mm, which can just be used as a "reference". For example, the standard wall thickness of the DN50 tube is 2.0mm, which is a little thicker than the coin; the standard wall thickness of the DN75 is 2.3mm, which is about half a millimeter thicker than the coin. If you feel that the wall thickness is similar to or even thinner than the coin when you touch the tube, it must be a "slimming tube" that cuts corners and passes directly.

Finally remember: these standard wall thicknesses cannot touch

According to the national standard GB/T 5836.1-2018, the minimum wall thickness of commonly used PVC drainage pipes must be satisfied: DN50 (outer diameter 50mm) 2.0mm; DN75 (outer diameter 75mm) 2.3mm; DN110 (outer diameter 110mm) 3.2mm; DN160 (outer diameter 160mm) 4.0mm. If the measurement is lower than this number, don't buy it no matter how cheap it is!

In fact, measuring the wall thickness is not "nitpicking", but "insurance" for decoration - after all, the drain pipe should be buried in the wall and underground. Once there is a problem, the rework cost is 10 times more expensive than buying a good pipe. Next time you buy a pipe, don't just listen to the merchant say "our pipe is fine", take out the tool and measure it twice, the data will not be deceptive. Learn these tricks, and you will no longer be afraid to buy "thin skin pipe"!