Tube in ECTFE SDR21 5000 mm natural

A tube in ECTFE is used where the medium is too aggressive for ordinary tube plastic. The material is a fluoropolymer that stands up to strong acids, bases, solvents and oxidizing substances, and keeps its properties over a wide temperature range. The density sits at about 1.68 g/cm³, a consequence of the fluorine content. The tube carries corrosive liquids and gases in process equipment where both the tightness and the chemical resistance are decisive and where a metal tube would quickly corrode or contaminate the medium with corrosion products.

The core is the chemical resistance. ECTFE is barely affected by media that dissolve or break down other plastics, and the smooth inner surface makes it hard for deposits to stick. That gives an even flow, low flow resistance and a reduced risk of clogging over time. The material takes up practically no moisture and handles both UV and weather, which makes the tubes usable even in exposed outdoor installations. The high working temperature compared with everyday plastics means the tubes handle hot media that ordinary plastic tubes cannot manage, and they keep their shape instead of softening.

Typical uses are lines for acids and bases in surface treatment, dosing and transport of reactive chemicals and process lines in the chemical and semiconductor industry where cleanliness is required. The smooth surface makes cleaning and flushing easier, and the material gives off no contaminants to the medium, which matters in purity sensitive processes where the product must not be contaminated. The tube is also used where temperature swings and chemical stress work together and wear out simpler materials before their time. Where a metal tube would corrode or a standard plastic break down, ECTFE stays tight and clean for a long time.

The tubes can be cut to length and joined by welding adapted for fluoropolymers. Since the material differs from ordinary engineering plastics, joining should be done by someone used to the technique, at the right temperature and with filler material that matches the tube. A well made joint keeps the same chemical resistance as the rest of the tube, while a careless joint becomes the point where the attack starts. Think through connections, fasteners and pressure conditions in the installation before you choose a dimension, and support the tube where it is needed so that it does not hang and load the joints.

Wall thickness and diameter decide both the pressure rating and how the tube behaves with temperature swings, so choose with margin against the operating conditions. Leave room for movement with heat changes, plastic tubes move more than metal. Store the tubes straight and supported so that they do not bend. We cut the tube in the lengths you need. If you want to make sure ECTFE handles your particular chemical, temperature and pressure, or whether another fluoropolymer or another wall thickness suits your installation better, get in touch and we will go through it together before you build.

Within the fluoropolymer family ECTFE is one of the mechanically tougher materials, and that shows in tubes exposed to both chemistry and flow carrying particles. The smooth inner surface keeps the flow even and works against deposits building up and choking the line, which otherwise forces cleaning or replacement. Against a metal tube, ECTFE wins because it does not corrode and does not add corrosion products to the medium, which is decisive in purity sensitive processes.

At installation the joints are what decide whether the line holds. A welded joint in the same material becomes as tight and resistant as the tube, while a poor joint becomes the point where it starts to leak. Give the line proper support so that the joints are not loaded by the weight of the tube itself, and leave room for movement with temperature swings because plastic moves more than metal.

Think through the whole run before you start: where the connections sit, where the tube needs support and where you can reach to inspect the joints. A well planned installation with the right support and well thought out joints gives a line that handles both the chemistry and the years. Store the tubes straight and supported until installation so that they do not bend.