Supplying domestic hot water to a building that rises one hundred meters or more is a mechanical problem long before it becomes a plumbing problem. The column of water alone loads the lowest floors with static pressure that a conventional low-rise distribution system was never designed to see, while the continuous hot service temperature silently attacks every joint, every elbow and every meter of pipe wall over a design life measured in decades rather than years. In this environment the pipe is not a passive conduit; it is a structural and hygienic component that must hold pressure, resist temperature, refuse to scale, and survive for fifty years without a single interruption. A three layer composite anti scaling PPR pipe extrusion equipment exists precisely because a single homogeneous pipe wall can no longer satisfy all of those duties at once.
The engineering answer is to stop asking one material to do everything and instead assign each function to a dedicated layer. A three-layer composite PPR pipe places an anti-scaling functional layer on the bore, a reinforcement or barrier layer in the middle, and a protective layer on the outside, co-extruding all three through one die in a single pass. The equipment that makes this pipe is therefore more than a ligne d'extrusion de tuyaux with extra hoppers; it is a tightly synchronized co-extrusion system in which layer ratio, melt viscosity, die geometry and cooling rate must be controlled together. This guide explains the full picture for equipment buyers and project engineers: why high-rise hot water demands the composite structure, how the three layers function, which materials and standards apply, exactly how the production line is built, what the process window looks like, how anti-scaling performance is measured, how the pipe is integrated into a tall building, and which Faygo production lines deliver it.
Faygo, une usine Wanplas with twenty-two years of dedicated pipe and profile extrusion experience, operates three specialized factories and runs a 26,650 square metre pipe, profile and sheet plant in Zhangjiagang, only two hours from Shanghai airport. The factory holds thirteen national patents including eight invention patents, and every line leaves the workshop Certifié CE et ISO after seventy-two hours of continuous operation testing. As part of the Wanplas group, Faygo draws on a shared engineering and service backbone that has placed plastic machinery in more than one hundred exported regions. The three-layer PPR co-extrusion line described here is a direct application of that experience to the specific failure modes of high-rise domestic hot water.
1. Four Hardships Facing Eau chaude domestique Systems in High-Rise Buildings
A high-rise domestic hot water network is defined by four stresses that ordinary low-rise plumbing never experiences together. Each stress alone is manageable; the four acting simultaneously on a single pipe wall are what make the composite structure necessary. Understanding these four hardships is the first step in specifying the right extrusion equipment, because the equipment must be capable of producing a pipe that answers all four at once.
1.1 Static pressure at the base of a tall column
In a building one hundred meters tall, the static head of the water column at the lowest riser connection is close to one megapascal before any pump pressure is added. With distribution pumps and thermal expansion, the bottom-floor service pressure in a one-hundred-meter building commonly reaches 1.0 to 1.2 megapascal. A single-layer random copolymer pipe sized for low-rise duty would need a very thick wall to carry that pressure, which only worsens the next two problems. The composite structure lets the middle layer carry stiffness and the inner layer carry the bore condition independently, so the pressure requirement does not force an oversized, thermally sluggish wall.
1.2 Long-term continuous hot water temperature
Domestic hot water is not a gentle, intermittent service. Circulation systems hold the riser at a continuous 60 to 70 degrees Celsius so that a tap delivers hot water promptly, and safety events such as a failed mixing valve can push short-term peaks to 95 degrees Celsius. Polypropylene random copolymer tolerates this band, but sustained temperature accelerates creep, softens the wall, and accelerates every chemical reaction at the bore, including scale deposition. The equipment must therefore extrude a pipe whose long-term hoop stress rating remains adequate at elevated temperature, which is why PP-RCT with its raised minimum required strength is offered as an inner-layer option.
1.3 Scaling and biofilm formation on the bore
Hard water carrying dissolved calcium and magnesium bicarbonate deposits calcium carbonate on any surface where nucleation can start. A rough bore, a polar surface, and warm stagnant pockets are ideal nucleation sites. Over years the deposit narrows the bore, raises flow resistance, and provides a habitat for biofilm. The inner anti-scaling functional layer of the composite pipe attacks this at the source: a mirror-smooth, low-surface-energy, optionally antibacterial bore that gives calcium carbonate almost nowhere to begin. This is the single most important reason the pipe is composite rather than homogeneous, and it is the property that the extrusion equipment must hold to tight tolerance across the full length.
1.4 Fifty-year design life
Les services de construction ne sont pas remplacés à la légère. Un riser enterré dans une trappe murale ou un puits est prévu pour fonctionner pendant la durée de vie du bâtiment, généralement cinquante ans, sans accès pour une inspection et sans tolérance pour les fuites. Cinquante ans de pression, de cyclage de température, de mouvement thermique et de chimie de l'eau exigent un conduit dont les propriétés ne ne pas dériver. Le composé à trois couches répond à cette exigence par la sélection des matériaux, le contrôle de l'expansion et une surface extérieure protégée, et l'équipement d'extrusion doit reproduire cette structure stratifiée mètre après mètre, sans délamination qui pourrait devenir une voie de défaillance à long terme.
Lorsque les quatre difficultés agissent sur un mur en même temps, la seule réponse robuste est de séparer les fonctions en couches. Cette séparation est exactement ce que l'équipement d'extrusion à trois couches est construit pour fournir.
2. Functional Layer Structure of the Three-Layer Composite Anti-Scaling PPR Pipe
The three-layer composite PPR pipe is engineered as three concentric functional zones, each optimized for one job and bonded to its neighbor by a compatible or tie-mediated interface. The layer ratio is deliberately imbalanced: the middle layer carries most of the wall because it carries most of the structural and barrier duty, while the inner and outer layers stay thin because they are functional skins rather than load-bearing members. The typical split is about 20 to 25 percent inner, 50 à 60 pour cent middle, and 20 to 25 percent outer by wall thickness.
2.1 Inner layer: the anti-scaling functional skin
The inner layer is the surface that touches the water, so its entire design goal is to make scale and biofilm unwelcome. Three mechanisms are combined. First, the bore is finished to a high smoothness with inner wall roughness Ra pas plus de 0,3 micromètre, compared with 0,8 à 1,5 micromètre for ordinary PPR, because fewer surface asperities means fewer nucleation sites for calcium carbonate crystals. Second, the polymer is modified for anti-fouling, either by an antibacterial additive package that suppresses microbial film or by a low-surface-energy modification that makes the water wet the wall uniformly instead of pinning droplets and deposits. Third, where temperature permits, the inner layer can be made from PP-RCT, the beta-crystal nucleated random copolymer, which raises the long-term temperature rating of the bore itself. Because this layer is thin, a premium modified compound can be used without making the whole pipe expensive.
2.2 Middle layer: reinforcement or barrier
The middle layer is the structural heart of the wall and the place where the designer chooses the dominant property the building needs. Two options dominate. The first is glass-fiber reinforced PP-R, loaded with 10 à 20 pour cent glass fiber, which cuts the linear expansion coefficient from about 0.15 to 0.03 to 0.05 millimeter per meter per Kelvin. For a vertical riser dozens of meters long, that reduction is decisive: it shrinks thermal movement, reduces the number and size of fixed supports and expansion compensators, and keeps the pipe from bowing in its chase. The second option is EVOH (copolymère d'éthylène et d'alcool de vinyle), an oxygen barrier used when the line is part of a closed heating circuit and must prevent oxygen from diffusing through the wall and corroding metal pumps, valves and radiators. With EVOH the oxygen permeability stays below 0.1 gram per cubic meter per day, satisfying the DIN 4726 limit for oxygen-tight plastic pipes. The choice between glass fiber and EVOH is a design decision made before the line is configured, and the co-extrusion equipment supports either.
2.3 Outer layer: protection and identification
The outer layer is the pipe’s skin to the world. It carries ultraviolet stabilizer so the pipe survives site storage and temporary exposure before embedding, abrasion resistance so it is not scored during installation, and color or stripe identification so installers can distinguish the anti-scaling composite from ordinary PPR at a glance. It also provides a weathering-resistant surface for the portions of pipe that may be exposed in plant rooms. Because it is a thin skin, it can be tinted or striped without affecting the structural or hygienic layers, which is why the composite pipe is often visibly marked as a special product.
2.4 Layer ratio and co-extrusion temperature matching
Holding the layer ratio constant along the full line is the central quality task of the equipment. The three melts have different viscosities and thermal sensitivities, so the co-extrusion temperatures must be matched so that no layer tries to dominate the interface. The table below shows the typical wall split and the temperature window in which the layers stay balanced. Getting this wrong is the root cause of most delamination and layer-thickness faults covered later.
| Layer | Fonction | Partage de mur typique | Co-extrusion temperature window | Key control point |
|---|---|---|---|---|
| Intérieur (fonctionnel) | Anti-scaling, smooth bore, optional PP-RCT | 20 to 25 percent | 200 à 225 degrés Celsius | Keep Ra low and layer centered on bore |
| Moyen (structure) | Barrière en verre-fibre renforcé PP-R ou EVOH | 50 à 60 pour cent | 210 to 235 degrees Celsius (GF higher) | Porter la tension de la corbeille et le contrôle de l'expansion |
| Couche extérieure (protection) | UV, abrasion, identification de la couleur | 20 to 25 percent | 195 à 220 degrés Celsius | Uniform skin, no streak or sink |
| Couche de liaison (si nécessaire) | Bond PP à EVOH ou GF-PP | 1 à 3 pour cent en général | 205 à 225 degrés Celsius | Adequate thermal match to both sides |
L'art de la tuyauterie à trois couches ne réside pas uniquement dans la chimie, mais dans le maintien de la proportion des couches et de la température de l'interface pendant des milliers d'heures de fonctionnement. L'équipement est évalué en fonction de sa cohérence, et non d'un seul échantillon de qualité.
3. Système de matériaux et normes pour les tuyaux PPR à trois couches
The composite pipe is only as good as the five materials that make up its layers and tie layers, and each material carries a specification that the raw-material system and the extrusion window must respect. The table below lists the core materials, their defining properties, and the roles they play. All values are typical engineering figures for pipe-grade compounds and should be confirmed against the specific compound certificate at procurement.
| Matériau | Propriété définie | Rôle dans la tuyauterie composite | Notes for the extrusion line |
|---|---|---|---|
| PP-R (copolyamide de type 3, aléatoire) | Vitesse de coulée de la masse fondue 0.25 to 0.5 gram per 10 minutes at 230 degrees Celsius and 2.16 kilogram | Polymère de base pour les couches interne et externe | Fenêtre de baril stable de 190 à 230 degrés Celsius |
| PP-RCT (nucleé de cristaux bêta) | Résistance minimale requise portée à 11,2 mégapascal | Option de couche interne à haute température | Nécessite un refroidissement contrôlé pour développer des cristaux bêta |
| PP-R GF (polypropylène renforcé de fibres de verre) | 10 à 20 pour cent glass fiber, lower expansion coefficient | Couche de renfort centrale | Abrasif ; baril et vis résistants à l'usure nécessaires |
| EVOH (copolymère d'éthylène et d'alcool de vinyle) | Teneur en éthylène de 32 à 44 pour cent de moles, barrière forte à l'oxygène | Couche de barrière intermédiaire pour les circuits de chauffage | Hygroscopic; requires dried feed and tie layer |
| Couche de liaison (PP-g-MAH) | Polypropylène greffé à l'anhydride mâleique | Bonds PP to EVOH or glass-fiber PP | Couche mince, correspondance de température étroite |
3,1 Normes qui régissent la tuyauterie
The finished pipe is judged against a stack of product and hygiene standards that the production line must be capable of satisfying. These are referenced as plain text only: ISO 15874 defines the PP piping system for hot and cold water installations; EN ISO 9080 governs the long-term hydrostatic strength extrapolation that sets the service life basis; DIN 8077 and DIN 8078 specify dimensions and the general quality requirements for PP pipes; GB/T 18742 is the Chinese national standard family for PP-R piping; ASTM F2389 covers PP pressure pipe for plumbing; NSF/ANSI 61 and NSF/ANSI 61-G certify the material for contact with drinking water; and EU 10/2011 regulates plastic food-contact materials, which for potable water means the additive package must stay within migration limits. The extrusion equipment does not itself certify the pipe, but it must be able to hold the dimensional and property consistency those standards demand.
3.2 SDR series and the pressure-temperature relationship
The standard dimension ratio, SDR, is the ratio of outside diameter to wall thickness and it sets the pressure class. For a given material the lower the SDR the thicker the wall and the higher the pressure rating. The table below shows common SDR values for PP-R composite pipe and the indicative pressure class at representative service temperatures. Indice de pressions decline with temperature because the polymer creeps faster when warm, which is exactly why the high-rise hot water duty must be read at 60 to 70 degrees Celsius, not at the 20-degree-Celsius catalog value.
| PN20 | Rapport d'épaisseur de paroi | Indicative PN at 20 degrees Celsius | PN indicatif à 60 degrés Celsius | PN indicatif à 70 degrés Celsius | Indicative PN at 80 degrés Celsius |
|---|---|---|---|---|---|
| SDR 6 | Thick wall | PN 20 | PN 10 à 12 | PN 8 to 10 | PN 6 to 8 |
| SDR 7.4 | Thick wall | PN 16 | PN 8 to 10 | PN 6 to 8 | PN 5 to 6 |
| SDR 9 | Medium wall | PN 12,5 | PN 6 to 8 | PN 5 to 6 | PN 4 |
| Norme ISO 60 | Medium-thin wall | PN 10 | PN 5 to 6 | PN 4 | PN 3.2 |
The pressure figures above are indicative relationships for planning, not a substitute for the calculated design stress from ISO 15874 using the specific compound’s long-term strength. They illustrate the critical point: a pipe that is PN 20 at room temperature may be only PN 8 at continuous 70-degree-Celsius hot water, and the composite structure is what lets the middle layer recover margin without thickening the bore-restricting wall.
4. Three-Layer Co-Extrusion Line: Extrudeur principal and Co-Extruders
Le cœur de la ligne de production est le groupe d'extrusion : un extrudeur principal qui fournit la masse de la couche intermédiaire fondue, ainsi que deux extrudeurs conjoints qui déposent les couches fines intérieure et extérieure. Étant donné que les couches diffèrent en volume d'un ordre de grandeur, les machines sont dimensionnées en conséquence. L'extrudeur principal est un grand appareil à un seul vis ; les extrudeurs de la couche extérieure sont de petits appareils précis à un seul vis dont la fonction est de déposer les couches plutôt que de produire une masse importante.
4.1 Extrudeur principal: single-screw with barrier screw
The main extruder uses a single screw of diameter 45 à 90 millimètres with an L/D ratio of 30 to 33 and a PP-specific barrier screw. The barrier section separates molten and solid polymer so that the melt delivered to the die is homogeneous and fully plasticized, which matters enormously for a glass-fiber or mineral-modified middle layer that must not contain unmelted agglomerates. Throughput scales with screw diameter and runs from about 120 kilogram per hour on the smallest main machine to about 800 kilogram per hour on the largest, which covers the full diameter range from 20 to 160 millimètres. The barrel is heated in independently controlled zones so the temperature profile can be tuned for PP-R, PP-RCT or the higher-temperature glass-fiber compound. For the glass-fiber middle layer the barrel and screw flight surfaces use wear-resistant treatment because glass fiber is abrasive and will otherwise erode the metering section within a season.
4.2 Deux extrudeurs pour les couches fonctionnelles
La couche anti-dégradation intérieure et la couche de protection extérieure sont chacune alimentées par un extrudeur conjoint de 30 à 50 millimètres de diamètre. Ces machines fonctionnent à faible rendement, mais doivent être dosées avec une stabilité élevée, car une variation de 1 % du débit de la couche extérieure modifie le rapport des couches et peut décaler la surface lisse intérieure. Elles utilisent la même philosophie de vis de barrière en miniature, avec un contrôle précis de la température afin que les composés fonctionnels fins, dont certains contiennent des additifs antibactériens sensibles à la chaleur, ne soient pas dégradés. Lorsque la couche intermédiaire est en EVOH, l'un de ces extrudeurs peut au lieu de cela alimenter la couche de liaison ou la barrière elle-même, et le moule distribue les couches en conséquence.
4.3 Equipment specification table
Le tableau ci-dessous résume le groupe d'extrusion pour une ligne à trois couches représentative. Les valeurs exactes varient en fonction de l'intervalle de diamètre et du choix des couches, mais l'architecture est constante dans toute la famille Faygo.
| Machine. | Diamètre de la vis | Rapport L/D | Type de vis. | Throughput | Tâche principale |
|---|---|---|---|---|---|
| Extrudeur principal | 45 à 90 millimètres | 30 à 33 | Vis de barrière en PP | 120 to 800 kg/h | Middle structural layer |
| Co-extrudeur 1 | 30 to 50 millimeter | 28 to 33 | Barrier screw | 10 à 60 kg/h | Couche anti-calcarisation intérieure |
| Co-extruder 2 | 30 to 50 millimeter | 28 to 33 | Barrier screw | 10 to 80 kg/h | Outer protection or tie layer |
| Melt pump (optional) | Matched to output | n/a | Gear pump | Stabilizes pressure | Layer uniformity |
4.4 Common debugging points for the extrusion group
When the layers drift, the cause is almost always in this group. A wandering inner-layer percentage usually traces to co-extruder screw speed instability or a feed starvation in the small hopper, which is why gravimetric or loss-in-weight feeding is preferred over volumetric for the skin lines. A lumpy middle layer points to insufficient plasticizing in the main barrel, corrected by raising the rear or middle zone a few degrees or by checking the barrier flight clearance. Glass-fiber streaking in the middle layer signals fiber agglomeration and calls for a review of the concentrate letdown and the screw shear. Stabilizing the extrusion group is the first task at every commissioning because every downstream station assumes a steady, well-melted feed.
5. Spiral Mandrel Co-Extrusion Die and Vacuum Calibration
The die is where three independent melts become one pipe. It is the most unforgiving component on the line, because any mismatch in layer flow shows up permanently in the finished wall. The three-layer co-extrusion die used for this pipe is a spiral mandrel die, chosen because the spiral distribution gives the most uniform circumferential layer thickness of any die geometry.
5.1 Spiral mandrel die and layer uniformity
A spiral mandrel die feeds each melt through a helical channel that wraps around the mandrel, merging the streams gradually so the layer arrives at the die land as a uniform annular sheet rather than as discrete feed points. For three layers the die stacks three such distribution systems around a common mandrel, each fed from its extruder. The design target is layer thickness uniformity within plus or minus 5 percent around the circumference, because a bore that is thin on one side loses its anti-scaling margin and a middle layer that is thin on one side loses pressure rating. The melt flow channels are shaped so that the interfaces stay flat and do not wave; interface waviness is a classic failure where the thin layer thickens and thins in a repeating pattern along the pipe and eventually breaks through. Temperature of the die body is held tightly, because a few degrees of gradient across the die land changes local viscosity and distorts the layer geometry.
5.2 Réservoir de calibration sous vide
Immediately after the die the pipe enters the vacuum calibration tank, where it is pulled onto a sizing sleeve under vacuum so that the outside diameter and roundness are set before the wall freezes. The calibration sleeve material is chosen for low friction and good heat extraction, often a treated aluminum or a sleeved steel, and its bore is the master dimension for the pipe. Vacuum is set in the range of minus 0.02 to minus 0.06 megapascal, enough to hold the soft pipe against the sleeve without collapsing it. Eau de refroidissement in the tank is kept at 12 to 18 degrees Celsius so that the outer surface sets quickly while the core stays workable long enough to avoid internal stress. Calibration is where ovality and outside diameter are locked in, so the tank length, water temperature and vacuum level are tuned together for each diameter and line speed.
5.3 Calibration and cooling parameter table
| Paramètre | Réglage typique | Effect if wrong |
|---|---|---|
| Calibration sous vide | minus 0.02 to minus 0.06 MPa | Too low: ovality; too high: collapse or sink |
| Température de l'eau de calibration | 12 to 18 degrees Celsius | Too warm: poor set, large shrinkage |
| Finition de la manche de dimensionnement | Low-friction, polished bore | Rough sleeve scores the outer skin |
| First tank length | Matched to diameter and speed | Short tank: incomplete set before haul-off |
5.4 Debugging the die and calibration
The most common die fault is circumferential layer variation, corrected by balancing the spiral channel feeds and confirming that all three extruders deliver steady pressure. Interface waviness is fought by narrowing the temperature gap between adjacent layers and by slowing the line slightly so the melt relaxes before freezing. Ovality that calibration cannot remove usually means the vacuum is uneven around the sleeve or the pipe is pulled off-center; checking the centering of the die to the tank and the vacuum porting resolves most cases. Because the die and calibration together define the pipe shape, they are commissioned together and only then handed to the cooling and pull stations.
6. En aval : refroidissement, transport, coupeur planétaire et inspection en ligne
Une fois que le tuyau a quitté le calibrage, il doit être refroidi dans toute sa paroi, tiré à une vitesse parfaitement constante, coupé sans bords, empilé et mesuré en continu. Le groupe en aval semble simple, mais c'est là que la stabilité de la vitesse de ligne et la qualité dimensionnelle finale sont déterminées.
6.1 Réservoir de refroidissement par pulvérisation
After the calibration tank the pipe passes through a spray cooling tank, usually built in multiple stages so that cooling is gradual rather than shock. Gradual cooling matters for the composite pipe because the glass-fiber middle layer and the PP skins cool and shrink at different rates; too fast a quench locks in internal stress that later shows up as warpage or, worse, as a hidden delamination driver. The outlet wall temperature is held inférieur à 40 degrés Celsius before the pipe reaches the haul-off, because a warm pipe stretches under pull and loses diameter control. Multi-stage spray also lets the line run faster for a given tank length, which is how the larger-diameter configurations reach their higher throughput.
6.2 Haul-off with synchronized belts
The haul-off grips the pipe between belts and pulls it at the speed that sets the final wall thickness through the draw-down ratio. For composite pipe the haul-off uses double or triple belts so the grip is distributed and the thin outer skin is not crushed, and the traction force and line speed are held in synchronization to entre plus ou moins 0,5 %. A drift in pull speed is the fastest way to make the wall thickness wander, because every percent of speed change is a percent of wall thickness change at the die. Belt pressure is tuned so the pipe is held without marking, and the drive is a closed-loop servo system referenced to an encoder on the belt.
6.3 Coupeur planétaire and collection
The planetary cutter travels with the pipe while cutting, so the cut is made without stopping the line and without burr. A rotating ring of blades orbits the pipe at the line speed, giving a square, clean cut face. Cut squareness matters because the pipe ends must be fusion-welded, and a skewed end makes a weak joint. After cutting, the length drops onto a tipping rack or is conveyed to a collection station where it is stacked for transfer to the test and packaging area. Because the composite pipe is heavier per meter than a single-layer wall of the same diameter, the collection system is sized for the actual finished weight, not for a light reference pipe.
6.4 Online inspection
Les lignes modernes comportent un contrôle continu plutôt que des échantillons par lots. Les capteurs ultrasoniques scannent la paroi et peuvent indiquer l'épaisseur de chaque couche si les couches ont des propriétés acoustiques distinctes, les capteurs laser mesurent le diamètre extérieur avec une précision de micromètre, et les caméras ou les sondes échantillonnent la surface lisse intérieure pour confirmer le finissage anti-dégradation. Un banc d'essai hydrostatique se trouve à la fin de la ligne ou dans la salle d'essai pour confirmer le taux de pression sur un échantillon représentatif. Les données d'inspection alimentent un contrôle de l'épaisseur de la paroi en boucle fermée qui modifie la vitesse de traction ou les sorties de l'extrudeur pour maintenir la paroi à la cible, de sorte que le tuyau reste dans les limites de tolérance pendant toute la production, et non seulement au début.
| Downstream station | Key parameter | Tolérance acceptée |
|---|---|---|
| refroidissement par pulvérisation. | Outlet wall temperature | inférieur à 40 degrés Celsius |
| Pose à l'air libre | Synchronisation de la vitesse et de la traction | entre plus ou moins 0,5 % |
| Coupeur planétaire | Cut face squareness | perpendicular within 1 degree |
| Online gauge | Diamètre extérieur et paroi | continu, corrigé en boucle fermée |
7. Process Parameter Tables for Three-Layer Co-Extrusion
La fenêtre de processus est l'ensemble des températures, pressions et vitesses qui maintiennent les trois couches dans leur ratio correct et le tuyau dans sa dimension correcte. Les tableaux ci-dessous constituent la référence de travail utilisée lors du démarrage et des changements de production. Ils sont des valeurs de référence techniques ; les chiffres exacts sont finalisés sur chaque ligne en fonction des composés choisis.
7.1 Barrel and die temperature profile
La couche principale en PP-R fonctionne à environ 190 à 230 degrés Celsius dans les zones du tube, avec la couche intermédiaire en fibre de verre chauffée un peu plus pour maintenir le composé rempli fluide, et la couche EVOH ou de liaison maintenue dans sa propre bande étroite pour protéger ses propriétés de barrière. Le corps de la matrice se trouve au sommet de l'intervalle afin que les mélanges restent uniformes pendant leur distribution. Trop froid et les couches ne se fondent pas ; trop chaud et les additifs se dégradent et l'interface s'étale.
| Zone. | PP-R inner / outer | Moyen en fibre de verre | EVOH / anneau central |
|---|---|---|---|
| Feed zone | 190 à 200 degrés Celsius | 195 à 210 degrés Celsius | 195 à 205 degrés Celsius |
| Compression zone | 205 à 215 degrés Celsius | 210 à 225 degrés Celsius | 205 à 215 degrés Celsius |
| Metering zone | 210 à 225 degrés Celsius | 220 to 235 degrees Celsius | 210 à 220 degrés Celsius |
| Méthylthiométhionine | 215 à 230 degrés Celsius | 220 to 235 degrees Celsius | 215 à 225 degrés Celsius |
7.2 Pression de la fusion, vacuum, cooling and speed matching
La pression du mélange au niveau de la matrice est maintenue entre 15 et 30 mégapascal afin que les couches soient pressées dans un contact étroit et que la distribution spiralée reste complète. Le vide, la température de l'eau et la vitesse de la ligne sont ajustés en fonction du diamètre, comme indiqué, et l'épaisseur de la paroi est maintenue par une boucle fermée qui relie la vitesse de traction à l'épaisseur mesurée. Les diamètres plus petits fonctionnent rapidement ; les diamètres plus grands fonctionnent lentement car la masse de paroi par mètre est beaucoup plus grande.
| Diamètre nominal | Pression de la fusion | Calibration sous vide | Eau de refroidissement | Vitesse de la ligne | Throughput |
|---|---|---|---|---|---|
| 20 millimeter | 15 to 22 MPa | minus 0.02 to 0.04 MPa | 12 to 18 degrees Celsius | 12 to 22 m/min | 120 à 180 kg/h |
| 32 millimètres | 16 à 24 MPa | moins 0,02 à 0,05 MPa | 12 to 18 degrees Celsius | 8 à 16 m/min | 150 à 240 kg/h |
| 63 millimeter | 18 to 26 MPa | moins 0,03 à 0,05 MPa | 12 to 18 degrees Celsius | 4 à 9 m/min | 180 to 320 kg/h |
| 110 millimètres | 20 à 28 MPa | minus 0.04 to 0.06 MPa | 12 to 18 degrees Celsius | 2 à 5 m/min | 300 à 600 kg/h |
| 160 millimètres | 22 to 30 MPa | minus 0.04 to 0.06 MPa | 12 to 18 degrees Celsius | 1.5 to 3.5 m/min | 380 à 800 kg/h |
7.3 Épaisseur de la paroi closed-loop control
The wall is not set once and forgotten. The online gauge reports outside diameter and wall, the control system compares them to the target for the selected SDR, and it trims the haul-off speed and the extruder outputs to remove drift. This closed loop is what lets a line hold tolerance across a full shift instead of only on the first spool. It also protects the expensive inner compound, because if the inner layer starts to wander thin the loop can compensate before the anti-scaling margin is lost.
8. Verifying and Quantifying Anti-Scaling Performance
La revendication anti-calcarisation n'est crédible que si elle est mesurée de la même manière à chaque fois et rapportée à un tube de référence. La méthode d'essai et le cadre de comparaison ci-dessous sont ceux qui ont été utilisés pour quantifier les performances de la couche intérieure et pour exprimer l'amélioration sous la forme d'un multiple relatif plutôt que d'une promesse absolue.
8.1 Scaling test method
The pipe sample is mounted in a loop through which hard water circulates at a calcium carbonate concentration of 300 to 500 milligram per liter, held at about 60 degrés Celsius, and run for 500 to 2000 hours. At the end the scale layer thickness and the mass increment per unit area are measured, the inner wall roughness is re-measured to see how much the bore has roughened, and the flow decay rate is calculated from the pressure drop at constant flow. A separate antibacterial check uses the ISO 22196 method, which counts bacterial reduction on the surface against a control. The whole battery is repeated on a reference single-layer PPR pipe of the same diameter and SDR so the comparison is fair.
8.2 Comparison against ordinary PPR
Because the inner surface of the composite pipe is smoother and lower energy, calcium carbonate nucleates far less readily, and the result is a much slower scale build-up. The table expresses the improvement as a relative multiple of the scaling rate of ordinary PPR, which is the honest way to state the benefit without implying a fixed lifetime number that depends on local water chemistry.
| Metric | PPR ordinaire (référence) | PPR anti-calcaire composite | Improvement |
|---|---|---|---|
| Roughness de la paroi intérieure Ra | 0,8 à 1,5 micromètre | pas plus de 0,3 micromètre | smoother bore |
| Scale mass increment | Reference value | lower multiple of reference | >scaling rate reduced severalfold |
| Flow decay after test | Reference value | lower multiple of reference | flow retained longer |
| Antibacterial activity | none | reduced count per ISO 22196 | biofilm suppressed |
The precise multiple depends on water hardness, temperature and flow velocity, so the equipment and the material are validated against the customer’s actual water where that data is available. What the extrusion line guarantees is the surface quality that makes the lower scaling rate possible: a bore that stays smooth and centered for the full length of every pipe.
9. System Design Support for High-Rise Applications
Making the pipe is only half the job; the pipe must be installed so that its properties are used correctly. The composite PPR pipe changes several design rules compared with a single-layer wall, and the equipment supplier should be able to advise on these so the finished building performs.
9.1 Zoned supply and pressure reduction
Because the base of a tall building sees 1.0 to 1.2 megapascal, the distribution is split into pressure zones, each served by its own riser and each protected by pressure-reducing valves so that no branch sees more than its rated pressure. The pipe grade and SDR are chosen per zone: lower zones use thicker SDR or PP-RCT inner layers, upper zones can use thinner walls. The co-extrusion line’s ability to hold SDR tightly is what makes this zoned design safe, because a wall that wanders thin would break the zone calculation.
9.2 Hot water circulation return
To avoid drawing cold water at every distant tap, high-rise systems use a circulation loop with a return pipe so water is always moving and always warm. Moving water scales more slowly than stagnant water, which complements the anti-scaling bore. The return loop also limits the time the pipe spends at peak temperature, extending the effective life. The pipe’s fusion joints must be planned so the loop can be balanced, and the composite pipe’s consistent wall makes joint heating predictable.
9.3 Thermal expansion compensation
Even with the glass-fiber middle layer cutting expansion to 0.03 to 0.05 millimeter per meter per Kelvin, a long vertical riser still moves with temperature, and that movement must be absorbed by expansion joints and anchored by fixed supports at planned intervals. The table gives indicative fixed-support spacing for the glass-fiber composite riser; the plain PPR value would be much shorter and would require far more anchors. Proper spacing prevents the pipe from buckling in its chase and prevents the joints from being loaded in bending.
| Diamètre | Espacement de support fixe (composite en fibre de verre) | Compensation method |
|---|---|---|
| 20 à 25 millimètres | about 2.5 to 3.0 meter | Expansion joint at riser base |
| 32 à 40 millimètres | environ 3,0 à 3,5 mètres | Joint plus supports de guide |
| 50 à 63 millimètres | environ 3,5 à 4,0 mètres | Joint plus supports de guide |
| 75 to 110 millimètres | environ 4,0 à 5,0 mètres | Joint plus large, moins d'ancrages |
9.4 Insulation and fusion joint parameters
Le montant est isolé pour maintenir la température de service et protéger les parties exposées contre les ultraviolets. Les joints sont réalisés par fusion à chaud, à une température de fusion de 260 degrés Celsius plus ou moins 10 degrés Celsius, et les temps de chauffage et de refroidissement sont calculés en fonction du diamètre. Le tableau ci-dessous donne les temps de chauffage et de refroidissement indicatifs ; ces valeurs de planification doivent être suivies sur le site. La paroi uniforme de la ligne d'extrusion rend ces temps fiables, car le chauffage rencontre la même épaisseur de paroi à chaque joint.
| Diamètre | Temps de chauffage | Temps de refroidissement | Température de la masse fondue |
|---|---|---|---|
| 20 millimeter | environ 5 secondes | about 2 minutes | 260 degrés Celsius plus ou moins 10 degrés Celsius |
| 32 millimètres | environ 8 secondes | environ 4 minutes | 260 degrés Celsius plus ou moins 10 degrés Celsius |
| 63 millimeter | environ 18 secondes | environ 7 minutes | 260 degrés Celsius plus ou moins 10 degrés Celsius |
| 110 millimètres | environ 35 secondes | environ 12 minutes | 260 degrés Celsius plus ou moins 10 degrés Celsius |
10. Lignes de production de tuyaux composites à trois couches PPR de Faygo
Faygo offers the three-layer composite PPR capability as configurations of its PP-R/PE-RT ligne d'extrusion de tuyaux, the same product family that covers PP-R and PE-RT pipes from 16 to 160 millimètres. Two configurations cover the diameter bands most relevant to high-rise domestic hot water, and both are built on the extrusion group, spiral mandrel co-extrusion die, vacuum calibration, spray cooling, synchronized haul-off, planetary cutter and online inspection described above. The specifications below are representative; final values are confirmed against the chosen layer structure and compound.
Configuration. A : diamètre petit à moyen, de 20 à 63 millimètres
Cette configuration cible les diamètres de branchements et de montants les plus courants dans les appartements et aux étages supérieurs d'un immeuble. Elle associe un extrudeur principal de taille moyenne à deux extrudeurs de revêtement co-extrudés et une matrice à spirale à trois couches. La ligne est suffisamment compacte pour occuper une surface modeste, mais couvre l'ensemble de la tuyauterie d'eau chaude des appartements. La couche interne lisse est produite à partir d'un bac dédié, de sorte que le composé anti-calcaire n'est jamais contaminé par la couche intermédiaire structurelle.
| Spécification | Configuration. A (20 à 63 millimètres) |
|---|---|
| Gamme de diamètre de la tuyauterie | 20 à 63 millimètres |
| Extrudeur principal | Single-screw 60 millimeter, L/D 33, Vis de barrière en PP |
| Co-extrudeur 1 (inner) | Vis à un seul écrou de 30 millimètres, L/D 30 |
| Co-extruder 2 (outer or tie) | Vis à un seul écrou de 45 millimètres, L/D 30 |
| Throughput | 120 à 260 kilogrammes par heure |
| Vitesse de la ligne | 4 à 22 mètres par minute (en fonction du diamètre) |
| Puissance installée | environ 145 kilowatts |
| Longueur de la ligne | environ 28 mètres |
| Couches de coextrusion | 3 (inner functional, middle GF or EVOH, outer) |
| Méthode de calibration | Manchon de calibration sous vide, water 12 to 18 degrees Celsius |
Configuration. B : diamètre grand, de 75 à 160 millimètres
This configuration serves the main risers and plant-room headers where wall mass and throughput are highest. It uses the largest main extruder in the family and the full three-layer die, and it is the line chosen when a project needs both the glass-fiber expansion control and the anti-scaling bore in one product at volume. The higher installed power and longer line reflect the greater cooling and pull load of the heavy large-diameter pipe.
| Spécification | Configuration. B (75 to 160 millimètres) |
|---|---|
| Gamme de diamètre de la tuyauterie | 75 to 160 millimètres |
| Extrudeur principal | Vis à un seul écrou de 90 millimètres, L/D 33, vis de barrière en PP |
| Co-extrudeur 1 (inner) | Single-screw 40 millimeter, L/D 30 |
| Co-extruder 2 (outer or tie) | Un seul vis de 50 millimètres, L/D 30 |
| Throughput | 320 to 800 kilogram per hour |
| Vitesse de la ligne | 1.5 to 10 meter per minute (by diameter) |
| Puissance installée | about 280 kilowatt |
| Longueur de la ligne | about 36 meter |
| Couches de coextrusion | 3 (inner functional, middle GF or EVOH, outer) |
| Méthode de calibration | Manchon de calibration sous vide, water 12 to 18 degrees Celsius |
Both configurations share the Faygo intelligent control system, which lets operators set parameters freely and adjust in real time, and both use internationally recognized brand electrical components for reliability. They leave the plant after the standard seventy-two-hour continuous operation test, which is where the layer consistency and the closed-loop wall control are proven before shipment.
11. Guide de sélection de la conception en fonction des exigences
The right configuration follows directly from the project’s diameter range, the required layer structure and the target output. The table below maps common high-rise hot water requirements to the Faygo PP-R/PE-RT ligne d'extrusion de tuyaux configuration that satisfies them. Where the duty is a closed heating circuit rather than potable hot water, the Barrière EVOH middle layer is selected instead of glass fiber.
| Gamme de diamètres | Structure de la couche | Sortie cible | Configuration. Faygo recommandée |
|---|---|---|---|
| 20 to 32 millimètres | 2 couches anti-calcul (intérieure fonctionnelle et extérieure) | 120 à 180 kg/h | Ligne PP-R/PE-RT, configuration A, mode à 2 couches |
| 20 à 63 millimètres | 3 couches avec une couche centrale en fibre de verre | 180 à 260 kg/h | Ligne PP-R/PE-RT, Configuration. A, 3-layer mode |
| 20 à 63 millimètres | 3 couches avec une barrière EVOH centrale | 180 à 260 kg/h | Ligne PP-R/PE-RT, configuration A, mode EVOH |
| 75 to 110 millimètres | 3-layer composite, GF or EVOH | 320 à 600 kg/h | Ligne PP-R/PE-RT, configuration B |
| 110 à 160 millimètres | 3-layer composite, GF middle | 500 à 800 kg/h | Ligne PP-R/PE-RT, configuration B, high-output |
| 20 to 110 millimètres | 3 couches avec une couche intérieure en PP-RCT, à haute température | 180 à 600 kg/h | Ligne PP-R/PE-RT, configuration A ou B avec option PP-RCT. |
Pour les projets qui nécessitent également d'autres familles de tubes, le groupe Wanplas peut fournir des lignes d'extrusion adjacentes, de sorte qu'un seul fournisseur couvre l'ensemble du package de services de bâtiment, mais dans le cadre de faygo-china.com, la recommandation reste dans la gamme de produits d'extrusion de tubes et de profilés Faygo.
12. Common Defects and Contramécanisme de sécurité Matrix
Even a well-designed line develops faults, and the composite structure has a few failure modes that single-layer pipe does not. The matrix below is the field reference used during commissioning and routine production. Each fault lists the likely cause and the corrective action, ordered so the operator can move from symptom to fix without guesswork.
| Défecte | Cause probable | Contramécanisme de sécurité |
|---|---|---|
| Épaisseur des couches uneven | Co-extruder speed drift, unbalanced spiral feed | Extrudeur à un seul vis avec alimentation gravimétrique ; rééquilibrage des canaux de la matrice |
| Déliumatin de la couche intérieure | La couche de liaison est insuffisante ou la température n'est pas compatible | Augmenter la couche de liaison ; réduire l'écart de température entre les couches |
| Grattures sur la paroi intérieure | Dommage au manchon de calibration, particules étrangères | Polish or replace sleeve; filter melt and clean feed |
| Fluctuation du diamètre extérieur | Déviation de la vitesse de déchargement, vacuum unstable | Recalibrate servo sync; check vacuum porting |
| Ovalité au-delà de la limite | Off-center die to tank, uneven vacuum | Matrice centrale ; équilibrage du vide autour du manchon |
| Peau de requin intérieure | Inner melt too cold or too fast at die land | Augmenter légèrement la température de la matrice de la couche intérieure ; réduire la vitesse |
| Bulles et marques d'eau | Humidité dans l'alimentation, en particulier pour l'EVOH | Dry EVOH and hygroscopic compounds; check hopper |
| Cut burr | Lame de coupe ébréchée, vitesse de suivi incorrecte | Sharpen or replace blade; match cutter to line speed |
| Échec du test hydrostatique | Wall below target, weak fusion, voids | Appliquer un contrôle de paroi en boucle fermée ; examiner la qualité des joints |
La plupart de ces défauts remontent aux mêmes deux thèmes : une mesure instable de l'extrudeur et un mauvais ajustement de la température à l'interface. Les lignes Faygo, avec leur alimentation gravimétrique sur les extrudeurs à paroi et leur contrôle strict de la température de la matrice, empêchent la plupart d'entre eux avant même qu'ils ne commencent.
13. Service et support de Faygo
Une ligne de production est un actif à long terme, et la valeur du fournisseur est évaluée au cours des années suivant la mise en service, autant qu'au moment de l'achat. Faygo, en tant que usine Wanplas, fournit les services partagés du groupe par le biais d'un programme de soutien défini qui commence avant l'expédition et continue pendant toute la durée de vie de la ligne.
13.1 Testing and commissioning
Every line is run for seventy-two hours of continuous operation at the factory before it is approved for shipment, so that layer consistency, wall control and line speed are proven under load rather than on paper. After arrival, Faygo engineers assist with installation and commissioning, bring the line to rated output, and run a trial production and sampling batch so the customer sees finished pipe before acceptance. The trial batch is also the moment to validate the anti-scaling bore finish and the hydrostatic sample against the project specification.
13.2 Pièces de rechange, formation et exploitation à distance
La politique de groupe de Wanplas prévoit une fourniture gratuite de pièces de rechange d'une valeur de 500 USD par an pour la ligne, avec un remplacement garanti pour les pièces endommagées pendant la période de garantie. Les opérateurs reçoivent une formation pratique sur la configuration, le changement de configuration et l'entretien de routine, et le système de contrôle intelligent permet un suivi à distance afin que les ingénieurs de Faygo puissent lire les données du processus et aider à résoudre les problèmes sans délai. Étant donné que la plateforme de contrôle stocke les recettes, un changement de diamètre ou de couche peut être reproduit de manière fiable une fois qu'il a été réglé.
13.3 Open factory and project services
Faygo welcomes customer visits to its Zhangjiagang plant, where the 26,650 square metre facility, the three specialized factories and the running lines can be inspected directly. Beyond the machine itself, Faygo offers factory consulting covering water and electricity design, three-dimensional workshop layout, worker configuration and training, and new-factory or capacity-expansion projects. For customers who need a complete building-services pipe package, the Wanplas group can coordinate adjacent extrusion lines so the whole scope is sourced and supported under one engineering responsibility.
Questions fréquemment posées
Why use a three-layer composite structure instead of a single-layer PPR pipe for high-rise hot water?
Un tuyau en PPR à une seule couche résiste à la pression et à la température, mais il ne peut pas contrôler simultanément la formation de tartre, l'entrée d'oxygène, la dilatation linéaire et la contamination de la surface. Le composite à trois couches sépare les fonctions : une couche fonctionnelle anti-tartre à l'intérieur maintient le diamètre lisse, une couche au milieu en fibre de verre ou en EVOH contrôle la dilatation ou la perméabilité à l'oxygène, et une couche extérieure de protection résiste aux rayons UV et aux dommages mécaniques. Cette séparation permet à chaque couche d'être optimisée sans compromettre les autres.
What is the difference between a glass-fiber middle layer and an EVOH middle layer?
Glass-fiber reinforced PP-R lowers the linear expansion coefficient from about 0.15 to 0.03 to 0.05 millimeter per meter per Kelvin, which stabilizes long vertical risers and reduces the number of fixed supports. EVOH (copolymère d'éthylène et d'alcool de vinyle) is an oxygen barrier used in closed heating circuits to stop oxygen diffusing through the wall and corroding metal pumps and valves, keeping oxygen permeability below 0.1 gram per cubic meter per day per DIN 4726. Many domestic hot water lines choose the glass-fiber version; heating systems choose EVOH.
Comment la performance anti-tartrage de la couche intérieure est-elle vérifiée ?
The standard approach circulates hard water with 300 to 500 milligram per liter calcium carbonate at about 60 degrés Celsius for 500 to 2000 hours, then measures scale layer thickness, mass increment, inner wall roughness and flow decay. Antibacterial function is checked by the ISO 22196 method. The result is compared against a reference single-layer PPR pipe to express scaling rate reduction as a relative multiple rather than an absolute figure.
Quelle configuration d'extrudeur utilise une ligne de co-extrusion de PPR à trois couches ?
The line uses one main single-screw extruder, typically diameter 45 à 90 millimètres with L/D 30 to 33 and a Vis de barrière en PP, plus two co-extruders of 30 to 50 millimeter for the inner functional layer and the middle or outer layer. A spiral mandrel co-extrusion die combines the three melts into a pipe with layer uniformity within plus or minus 5 percent.
Which Faygo production line fits a given diameter and layer structure?
Pour les tuyaux PPR à trois couches de 20 à 63 millimètres, la ligne d'extrusion de tuyaux Faygo PP-R/PE-RT dans la configuration de petit à moyen diamètre couvre une production de 120 à 260 kilogrammes par heure. Pour les tuyaux composites à trois couches de 75 à 160 millimètres, la configuration de grand diamètre couvre une production de 320 à 800 kilogrammes par heure. Ces deux configurations appartiennent à la même famille de produits de la ligne d'extrusion de tuyaux Faygo PP-R/PE-RT et partagent le calibrage sous vide, la coupe planétaire et l'inspection en ligne.
What melt temperature and calibration conditions are typical for three-layer PPR?
The PP-R base layers run about 190 à 230 degrés Celsius in the barrel zones, with the glass-fiber or EVOH layer run somewhat higher to match viscosity. Pression de la fusion at the die is 15 to 30 megapascal, vacuum calibration is set at minus 0.02 to minus 0.06 megapascal with cooling water at 12 to 18 degrees Celsius, and the outlet wall temperature from the spray tank stays inférieur à 40 degrés Celsius before the haul-off.
Comment Faygo assure-t-il l'installation et le service après-vente pour une ligne complète ?
Every line is run for 72 hours of continuous operation testing before delivery, then engineers assist with installation and commissioning, trial production and sampling. The Wanplas group policy provides USD 500 free spare parts per year plus warranty replacement, Assistance technique en ligne 24/7, operator training and an open factory welcome for customer visits and audits.
Conclusion
The domestic hot water system of a one-hundred-meter building asks more of its pipe than any low-rise network: it demands pressure resistance at the base, temperature endurance at the top, a bore that refuses to scale for fifty years, and a wall that does not buckle as it heats and cools. A three-layer composite anti-scaling PPR pipe answers all four by assigning each duty to its own layer, and the extrusion equipment that makes it is a synchronized co-extrusion system built around a stable extrusion group, a spiral mandrel die, vacuum calibration, steady haul-off and continuous inspection.
Faygo, une usine Wanplas with twenty-two years of pipe and profile extrusion experience, builds this capability into its PP-R/PE-RT ligne d'extrusion de tuyaux in configurations covering 20 to 160 millimètres, with the layer structure, throughput and control needed for genuine high-rise duty. Every line is proven over seventy-two hours before shipment, supported by the Wanplas group’s USD 500 free spare parts per year policy, remote operation assistance and open-factory access.
If you are specifying equipment for a high-rise domestic hot water project, send us your diameter range, target output, layer structure and local water chemistry. Our engineering team will return a tailored line configuration, arrange a trial production and sampling at our Zhangjiagang plant, and walk you through commissioning and operator training so the pipe you make meets the building’s fifty-year expectation from the first meter to the last.
