--- title: "Polyether vs Polyurethane Tubing: How to Choose" canonical: "https://yuannaitube.com/polyether-vs-polyurethane-tubing/" language: "en-US" --- RESOURCES # Polyether vs Polyurethane Tubing: How to Choose By [YUANNAI TUBE]() Published 2026-10-23Updated 2026-11-05 ![Translucent blue and opaque orange polyurethane tubing coils with water droplets]() **Polyether polyurethane tubing (polyether TPU)** and standard polyester-based **PU tubing** are both elastic polyurethane products, produced here in the same sizes with the same tolerance — but their pressure ratings and bend radii differ in a consistent, measurable way. This comparison uses our own model tables for both ranges, so you can pick the grade from numbers rather than adjectives. **Quick answer.** At the same metric size, the polyether range (YN-PUR) carries a higher **working pressure** than the standard PU range (YN-PU) — for example 12 bar versus 7 bar on the 8 × 5 tube. PU bends tighter at the same size, which suits moving parts. In fractional sizes from 1/8″ to 1/2″ the ratings are identical, so there the environment decides, not pressure. ## Ether vs. Ester Polyurethane: Understanding the Polymer Chemistry Both ranges are elastic **polyurethane tubing**, and both are dimensioned the same way: outside and inside diameter in millimeters with ±0.10 mm tolerance, metric from 4 mm to 16 mm OD plus fractional sizes. The difference is the grade. The [PU tubing range]() uses the YN-PU model prefix; the [polyether tubing range]() is the polyether-TPU grade with the YN-PUR prefix. Polyether chemistry is the established choice when moisture is part of the service: polyether grades hold up better in warm, humid conditions and in water-adjacent service than general-purpose polyurethane, which the [pneumatic tubing guide]() flags as vulnerable to hydrolysis in exactly those conditions. Pressure and flexibility still decide most size choices, so start there. ## Working pressure: the same size is not the same rating Ten metric model codes exist in both ranges with identical dimensions, which makes a direct comparison possible. Every figure below comes from our own published model tables. | Model (same size) | YN-PU working pressure | YN-PUR working pressure | YN-PU min. bend | YN-PUR min. bend | | --- | --- | --- | --- | --- | | 0425 (4×2.5) | 8 bar (128 psi) | 10 bar (145 psi) | 10 mm | 15 mm | | 0640 (6×4) | 8 bar (128 psi) | 10 bar (145 psi) | 15 mm | 25 mm | | 0850 (8×5) | 7 bar (116 psi) | 12 bar (175 psi) | 20 mm | 30 mm | | 0855 (8×5.5) | 6 bar (99 psi) | 8 bar (116 psi) | 22 mm | 40 mm | | 0860 (8×6) | 5 bar (75 psi) | 8 bar (116 psi) | 25 mm | 40 mm | | 1065 (10×6.5) | 7 bar (106 psi) | 10 bar (145 psi) | 25 mm | 40 mm | | 1080 (10×8) | 6 bar (94 psi) | 8 bar (116 psi) | 30 mm | 45 mm | | 1280 (12×8) | 7 bar (104 psi) | 10 bar (145 psi) | 50 mm | 50 mm | | 1410 (14×10) | 7 bar (106 psi) | 10 bar (145 psi) | 70 mm | 70 mm | | 1612 (16×12) | 7 bar (109 psi) | 8 bar (116 psi) | 95 mm | 95 mm | *Fractional sizes tell a different story: the 1/8″, 1/4″, 3/8″ and 1/2″ tubes carry identical ratings in both ranges (12, 10, 10 and 8 bar respectively). The standard PU range adds a 3/4″ size the polyether range does not list.* The pattern is consistent: on metric sizes the polyether grade is rated higher across the board — up to 12 bar versus 7 bar on the 8 × 5 tube. If a metric line runs close to a PU range ceiling, the polyether model of the same size usually has headroom. ## Flexibility: PU bends tighter The second column pair inverts the story. At the same size, PU takes a smaller **bend radius** — 10 mm versus 15 mm on the 4×2.5, 20 mm versus 30 mm on the 8×5. On the three largest metric sizes the radii are equal. For routes with tight corners or moving assemblies, the PU range keeps its margin; the [bend radius guide]() explains how to measure and lay out a route against these values. ## Environment: Polyurethane Hydrolysis Resistance & Microbial Defense **Polyurethane hydrolysis** is the primary degradation mechanism for standard polyester-based PU in warm, humid air: moisture attacks the ester backbone, causing embrittlement and cracking over months of service. In contrast, **polyether polyurethane tubing** is chemically immune to hydrolytic degradation and resistant to fungal/microbial attack, making it the essential specification for washdown zones, water treatment lines, and tropical climates. Polyether is the standard answer for hydrolysis-prone conditions, while polyester-based polyurethane is the grade that degrades there. Where the line carries oil mists or aggressive media, neither grade is the automatic answer — check the [fluoropolymer comparison]() before committing. ### What to record when PU tubing ages in service If a polyurethane line has turned tacky, stiff or cracked, record the evidence before replacing it, so the next grade is chosen from facts: - **Appearance and feel:** surface tack, whitening or haze, and stiffness compared with an unused piece of the same model. - **Crack location:** outer side of a bend, at the fitting, or along a straight section. - **Exposure:** moisture or condensate in the line, washdown or outdoor contact, the temperature range, and any oil mist or cleaning agent. - **Time in service:** installation date and the model marking printed on the tubing. Send these notes with a photograph and an unused sample of the same model through the [contact page]() , and compare the exposure against the grade you used. The [BASF Elastollan brochure]() states that polyether polyols give the highest hydrolysis resistance and resistance to microbiological degradation. The [sample testing guide]() shows how to check a replacement before a bulk order. Typical placements: [pneumatic automation]() runs inside panels (either grade, sized by pressure), wash and coolant supply described on the [cleaning and industrial water page]() (polyether default), and general air tools (PU for the tighter bends on portable runs). ### Water, sunlight and cold are separate checks Hydrolysis resistance answers one question: what moisture does to the polymer chain. It does not tell you how a tube behaves in sunlight or in the cold, so state each exposure on its own when you specify a line. The [BASF Elastollan material properties document]() describes these as separate effects for thermoplastic polyurethane in general; it is a raw-material reference, not a rating for our tubing. - **Water and humidity:** BASF states that polyester-based polyurethane exposed for lengthy periods to hot water, moisture vapor or tropical climates suffers irreversible chain breakdown, and that polyether-based grades are much more resistant. Say which applies to your line: continuous immersion, intermittent water contact, or only humid air, plus the water temperature. - **Sunlight (UV):** BASF describes UV ageing of polyurethane as surface embrittlement with yellowing and a loss of mechanical properties, delayed by UV stabilizers and pigments, with dark colors such as black masking the discoloration. A polyether grade is not automatically UV resistant, so list outdoor exposure separately and ask whether the tube is stabilized. - **Cold:** BASF lists best low-temperature flexibility for polyether polyols and reports low-temperature impact strength as a separate property. How easily a tube bends when cold and whether it survives a knock when cold are different questions, so state the lowest temperature and whether the line moves or can be struck. BASF also notes that glass transition values depend on the test method, so compare low-temperature figures only when they come from the same method. For our tubing, the temperature range on each [product page]() is the starting point, and the [working pressure and temperature review]() explains why pressure and temperature are read together. ### What a symptom can point to Use the observation in your notes to decide which exposure to check first. The pairings below come from the [BASF Elastollan material properties document]() and describe polyurethane in general, not a diagnosis of a specific tube. | What you see | Exposure to check first | What BASF states | | --- | --- | --- | | Yellowing, then a brittle surface | Sunlight (UV) | UV ageing shows first as surface embrittlement with yellowing and a loss of mechanical properties. | | Discoloration, then surface cracks, in a hot and humid place | Microbial attack on polyester-based polyurethane | Attack is visible first as discoloration, then surface cracks; polyether-based polyurethane is resistant. | | Loss of strength after long contact with hot water, moisture vapor or a tropical climate | Hydrolysis of polyester-based polyurethane | The polyester chains break down irreversibly, and polyether-based grades are much more resistant. | | Swollen, softer tube after contact with alcohol, an ester or a solvent | Liquid absorption (swelling) | Ethanol and isopropanol cause swelling with a loss of tensile strength; esters cause severe swelling; swelling reverses as the liquid evaporates. | | Tacky surface after contact with bleach | Chemical attack by the cleaning agent | Its test table lists a tacky surface for sodium hypochlorite bleach. | BASF itself says these effects cannot always be separated cleanly and recommends a specific stability test for a particular application. Whitening, haze and hardening are not covered by a general rule in that document, so record them with the exposure notes above and send them with a sample rather than guessing a cause. ## How to choose in four checks **1. Pressure at temperature.** Find the closest size in the table above; if the PU rating is marginal, the same-size polyether model adds margin. Ratings hold at the stated temperature — the [working pressure and temperature review]() covers derating. **2. Routing.** Tight bends at small sizes favor PU; generous sweeps make the grades interchangeable on flexibility. **3. Environment.** Warm, humid or wet service points to polyether; dry, ambient air inside a panel points to whichever grade the fittings and budget favor. **4. Fittings.** Both ranges share the same outside diameters and ±0.10 mm tolerance, so push-to-connect and compression fittings accept either — confirm the hardness range the fitting manufacturer specifies (our values are on the [tubing Shore hardness]() page). The fuller selection logic, including the nylon alternative for static high-pressure routes, is in the [PU vs nylon selection checklist]() . ## Ordering Send the inside and outside diameter (or fitting model), total length, quantity, the medium and its temperature range, and the **working pressure** at that temperature; the [quotation checklist]() lists every field. If you are unsure which grade fits, send the same five items and ask for both to be quoted — the price difference is settled by the quotation, not by this guide. An overview of where both ranges sit among the other materials is on the [industrial tubing materials page]() . For polyurethane against polyethylene, see [PU vs PE tubing]() . If you need static control or several channels in one piece, [antistatic PU tubing]() and [multi-lumen tubing]() are made to order. ![PU Tubing — blue, red and transparent reels with AIR PASSAGE logo]() Fig. 1: Factory stock of polyether and standard polyurethane tubing reels organized by outer diameter. ## Polyether vs PU FAQ What causes polyurethane hydrolysis in compressed air tubing lines? Polyurethane hydrolysis occurs when moisture and heat combine to break down the ester linkages in standard polyester TPU. In compressed air systems with inadequate desiccant drying, water vapor condenses on the tube inner wall; at temperatures above 30°C, this accelerates molecular degradation, causing the tubing to become brittle and burst. Specifying polyether-grade TPU (YN-PUR) eliminates this failure mode because ether molecular bonds do not react with water. How can you tell if a tube is polyether-based or polyester-based TPU? Visually, high-grade virgin **polyether tubing** tends to offer higher initial optical clarity and better cold-temperature flexibility (down to -40°C). On model specifications, YUANNAI TUBE designates polyether grades with the YN-PUR code, which also features higher metric **working pressure** ratings (up to 12 bar on 8×5 mm) compared to standard YN-PU (7 bar). Is polyether tubing the same as polyurethane tubing? Polyether is a grade within the polyurethane family: both are elastic thermoplastics, and the two ranges here share the same sizes, tolerances and fitting compatibility. The YN-PUR range is the polyether-TPU grade, specified separately because its pressure ratings and moisture behavior differ. Which grade carries higher pressure? On metric sizes, the polyether range is rated higher at every size in the table — for example 10 bar versus 8 bar on the 4×2.5 and 12 bar versus 7 bar on the 8×5. In fractional sizes from 1/8″ to 1/2″, the two ranges carry identical ratings. Which one bends tighter? The PU range takes smaller minimum bend radii at the same metric size — 10 mm versus 15 mm on the 4×2.5, 20 mm versus 30 mm on the 8×5. The radii are equal on the 12, 14 and 16 mm sizes. Which grade should I use in a humid environment? Polyether is the default for warm, humid or water-adjacent service; general-purpose polyurethane is the grade that suffers from hydrolysis in those conditions. If the medium itself is aggressive rather than the air, compare the fluoropolymer options instead. Do the two grades use the same fittings? Yes on size: identical outside diameters and the same ±0.10 mm tolerance mean the same push-to-connect and compression fittings fit both ranges. Confirm the hardness range the fitting manufacturer accepts, since the grades differ in hardness as well as strength. **Next step.** Compare the full model tables on the [PU tubing page]() and the [polyether tubing page]() , or see the whole range on the [product overview]() . ## Sources and scope - [Polyether Tubing — English data sheet (v2-20261020)]() - [PU Tubing — English data sheet (v3-20261020)]() 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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