Drainpipe PVC Selection Guide: From Specifications to Performance

2025-08-19

In decoration or engineering construction, the selection of PVC drain pipes is an easily overlooked but far-reaching link - choose the right one to avoid leaks, blockages, loud noises and other unpleasant problems in the later stage; choose the wrong one, you may face rework as soon as you move in. Today, from specifications to performance, we will teach you to choose the right PVC drain pipe step by step.

First, understand the specifications: how to choose the diameter, wall thickness and length?

PVC drain pipe specifications mainly look at three dimensions: pipe diameter, wall thickness and length, which directly determines the applicable scene.

1. Pipe diameter: corresponding to different drainage needs

pipe diameter refers to the nominal diameter (DN) of the pipe, commonly used are DN50, DN75, DN110, DN160 and so on. For example:

- sink, balcony laundry pool: small displacement, DN50 is enough;

- shower area, kitchen sink: medium displacement, DN75;

- toilet, main drain: large displacement and debris, must choose DN110 and above;

- engineering riser or underground pipe network: DN160 or even larger diameter may be used.

The key to choosing the diameter is to match the drainage flow - the toilet has a large instantaneous displacement, and DN50 will block it; DN110 for the sink is a waste.

2. Wall thickness: light vs heavy, do not choose the wrong scene

PVC pipe wall thickness is divided into light (L type), heavy (M type), super heavy (H type):

- the drain pipe in the family ceiling: choose light pipe (wall thickness about 2.0mm), do not bear load;

- buried or engineering pipe: choose heavy (about 3.2mm) or even super heavy, resistant to soil pressure, anti-stampede;

- kitchen: because of oil and hot water, it is recommended to choose a slightly thicker wall thickness, more durable.

3. Length: fixed length vs customization, taking into account the installation efficiency

PVC pipe is usually fixed length 4 meters/root, easy to transport and install; special scenes (such as loft high floor) can be customized, but too long pipe is not easy to handle, easy to bend.

Second, performance is the core: these points can not be ignored

specifications selected, but also depends on whether the performance matches the needs, after all, the "job" of the drain pipe is efficient and stable drainage.

1. Drainage capacity: flow rate and flow rate are the key

drainage capacity and pipe diameter, slope, inner wall smoothness. For example, DN110 pipe at a slope of 0.025, the flow speed of 1.5m/s, flow about 0.015m ³/s, just to meet the needs of the toilet. If the slope is too small (sacrifice slope for beauty), even if the pipe diameter is large, it is easy to accumulate water and block the pipe.

2. Corrosion resistance: kitchen bathroom "life saver"

PVC pipe anti-acid and alkali, anti-oil stain - kitchen detergent water, toilet shampoo water will not corrode it; and metal pipe easy to rust blockage, PVC do not have to worry.

3. Impact resistance: buried or public areas should focus on

community underground pipe is often rolled by vehicles, heavy PVC pipe impact resistance is strong, with a hammer will not break; family buried pipe selection impact resistance is good, to avoid the decoration of workers trampling damage.

4. Sound insulation: choose "quiet pipe" for household use

Ordinary PVC pipe drainage has "rushing" noise, and the inner wall of the spiral silencer pipe has spiral lines to guide the flow of water along the pipe wall and reduce impact noise. It is more than 30% quieter than ordinary pipes and is suitable for family bathrooms.

three, avoid these selection errors, less detours

many people choose to make these mistakes:

- only look at the price of thin-walled pipe: buried with light pipe is easy to be soil fracturing, later rework costs are higher;

- blindly choose large pipe diameter: kitchen with DN110 is not necessary, waste money and take up space;

- ignore the compatibility of accessories: pipe fittings and pipes of different brands/specifications, easy to lead to water leakage;

- do not look at the test report: inferior pipe with water recycling material, brittle to break a crack, to choose products that meet GB/T 5836.1-2018 standards.

Finally: Summarize the selection of "three-step method"

1. Set the scene: family bathroom choose DN110 spiral pipe + heavy wall thickness; engineering buried heavy pipe;

2. Select specifications: according to the scene to determine the pipe diameter (toilet DN110, wash basin DN50), wall thickness (household light/heavy, engineering heavy), length (fixed length 4 meters);

3. Check performance: drainage capacity (see flow rate), corrosion resistance (PVC no problem), sound insulation (household spiral pipe), impact resistance (buried with heavy);

4. Check accessories: pipe fittings should be the same brand with the same specifications, such as DN110 pipe with DN110 elbow to avoid leakage.

It is not difficult to choose a PVC drain pipe. The key is to "choose on demand" - first think clearly "where to use" and "what problem to solve", and then choose the specifications and performance to avoid 90% of the pits. After all, the drain pipe is a "hidden project". Choose the right one at a time and worry for ten years.


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