--- title: "PU Pipe and Pneumatic Pipe vs Tubing: Sizes and Ordering" canonical: "https://yuannaitube.com/pu-pipe-pneumatic-pipe-vs-tubing/" language: "en-US" --- RESOURCES # PU Pipe and Pneumatic Pipe vs Tubing: Sizes and Ordering By [YUANNAI TUBE]() Published 2026-10-28Updated 2026-11-03 ![Straight lengths of blue, orange, black and clear PU tubing beside a coil and push-in fittings]() ## PU pipe and pneumatic pipe: the short answer In many markets, “PU pipe” and “pneumatic pipe” are everyday names for flexible polyurethane (or nylon) tubing on compressed-air lines. The name matters less than the specification. To order the right tube, state the material, the **outer diameter** (OD), the **inner diameter** (ID) and the length. A “6 mm PU pipe” is most often a 6 mm OD tube, but confirm the OD and the ID in writing before you order. ## Pipe, tube, tubing and hose: what the words mean | Word | Usually means | What to specify | | --- | --- | --- | | PU pipe, pneumatic pipe | Flexible plastic tubing for air lines, sold on a roll | Material, OD and ID, length, color | | Tubing, tube | The same flexible product, the term used on data sheets | Model number, OD and ID, working pressure | | Hose | A heavier or reinforced flexible line, often with fixed end fittings | Inner diameter, working pressure, end fittings | | Pipe (rigid) | Steel, copper or PVC pipe that is not coiled on a roll | Nominal size and pressure class | Because “pipe” can also mean rigid pipe, always add the material and the OD/ID when you ask for a flexible air-line pipe. Our [tubing glossary]() defines each term. ## PU tubing sizes sold as PU pipe These are the metric sizes in our **PU tubing** model table, written OD/ID in mm. A tube is named by its OD because the OD has to match the push-in fitting. | Common name | OD/ID (mm) | Wall (mm) | | --- | --- | --- | | 4 mm PU pipe | 4/2.5 | 0.75 | | 6 mm PU pipe | 6/4 | 1.0 | | 8 mm PU pipe | 8/5, 8/5.5, 8/6 | 1.5, 1.25, 1.0 | | 10 mm PU pipe | 10/6.5, 10/8 | 1.75, 1.0 | | 12 mm PU pipe | 12/8 | 2.0 | | 14 mm PU pipe | 14/10 | 2.0 | | 16 mm PU pipe | 16/12 | 2.0 | Inch sizes (1/8, 1/4, 3/8, 1/2 and 3/4 in) are separate sizes. A 6 mm tube is not a 1/4 in tube; they differ by 0.35 mm. See the [PU tubing models]() and the [tubing size chart]() . ## What to put in a PU pipe order 1. **Material:** standard PU, [polyether PU]() for damp conditions, or nylon ( [PA6]() , [PA12]() ) where pressure matters more than flexibility. See [PU vs nylon]() . 2. **Size:** OD/ID in mm, for example 8/5. 3. **Length:** the roll size or the cut length, and the quantity. 4. **Color:** standard or a reference. 5. **Conditions:** medium, **working pressure** and temperature. Then [request a sample]() of the exact size, or [send your requirements]() . ## Frequently asked questions Is PU pipe the same as PU tubing? For compressed-air work, yes: both names describe flexible **polyurethane tubing** sold on a roll. Data sheets use “tubing” and give the OD and ID, which is the safest way to specify it. Is a 6 mm PU pipe 6 mm OD or 6 mm ID? It is usually the OD, so a 6/4 tube. Because buyers use the name in different ways, write both the OD and the ID in your order, for example 6/4 mm. What is the difference between PU pipe and nylon pipe? PU is more flexible and bends at a tighter radius. Nylon (PA6, PA12) carries a higher **working pressure** at the same size. Compare both in the [pressure table by size]() . Which fitting fits a PU pipe? A push-in fitting takes the OD of the tube: a 6 mm fitting takes a 6 mm OD tube. See [matching tubing to fittings]() . **Related guides:** [nylon 12 (PA12) tubing]() . ## Sources and scope - [PU Tubing — English data sheet (v3-20261020)]() - [PA6 Nylon Tubing — English data sheet (v4-20261020)]() - [PA12 Nylon Tubing — English data sheet (v5-20261020)]() Use these documents for the identified product models and stated test conditions. General material comparisons and selection checklists do not establish a different grade’s rating, fitting compatibility or project approval. Confirm the exact model, medium, temperature, pressure and required evidence before ordering. Content review: [zhangkexin]() · Marketing Review scope: market information and document references. ## Tell us what your application needs. Send your dimensions, operating conditions and quantity. Let’s identify the right tubing for your project. 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