Why Anti-Corrosion PE Pipe Defines the Ground Source Heat Pump Loop
Anti-corrosion PE ground source heat pump pipe is the buried heat exchanger of every geothermal central heating system, and the quality of that pipe decides whether the loop still performs in year forty or fails in year five. Once a vertical borehole is grouted or a horizontal trench is backfilled, the pipe becomes unreachable. There is no inspection hatch, no valve to isolate a leaking segment, and no economical way to replace a buried U-bend without redrilling. That single fact is why geothermal contractors specify polyethylene rather than steel or copper, and why the extrusion equipment that produces the pipe has to hold wall thickness, ovality, and melt quality to a much tighter standard than general-purpose water pipe.
Ground source heat pump projects have grown from scattered residential installations into district-scale geothermal central heating pipeline engineering, serving apartment blocks, schools, hospitals, office parks, and industrial campuses. A single district loop field can consume tens of kilometers of PE pipe in diameters from 16 mm capillary circuits up to 160 mm and larger header mains. Pipe producers who want to serve that demand need an extrusion line that runs PE100 and PE-RT compounds cleanly, coils small diameters without kinking, and delivers consistent dimensions shift after shift.
Faygo, a Wanplas factory, has spent 22 years building plastic pipe and profile extrusion lines and operates three specialized factories dedicated to this category. The FAYGOPLAST plant in Zhangjiagang covers 26,650 square meters and sits roughly two hours from Shanghai Airport, and the factory holds 13 national patents, 8 of them invention patents. Faygo pipe extrusion equipment covers a diameter range of 12 mm to 575 mm across PE, PP, and PVC, and every line is CE and ISO certified and runs a 72-hour continuous operation test before it is released for shipment. For a geothermal pipe producer, that combination of range and pre-delivery proof is what turns a machine purchase into a working production asset.
This article works through the whole picture: how a ground source heat pump loop uses PE pipe, why polyethylene resists corrosion in aggressive soils, how PE100, PE80, and PE-RT differ for geothermal service, what each section of a PE pipe extrusion line does, which Faygo line configurations match which pipe programs, how to set and control process parameters, how loops are joined and pressure tested, how PE compares with metal alternatives, and how to select the right line for a specific production plan. Specification tables, a requirement-to-model selection table, a relative investment table, and a frequently asked questions section are included so the article can be used as a working reference rather than a one-time read.
Table of Contents
Use the anchors below to jump to any section on this page:
- Why anti-corrosion PE pipe defines the ground source heat pump loop
- How a ground source heat pump loop works and where the pipe sits
- Why polyethylene resists corrosion underground
- PE100, PE80, PE-RT and PEX for geothermal loops
- Anatomy of a PE ground source heat pump pipe extrusion line
- Faygo PE pipe extrusion line: specifications and configurations
- Process parameters and dimensional quality control
- Faygo PE-RT and PP-R pipe extrusion line for small-diameter circuits
- Joining methods, loop assembly, and pressure testing
- Thermal performance and loop field design
- PE ground loop pipe compared with metal and composite options
- Selection guide: matching your pipe program to a Faygo line
- Application industries and geothermal project types
- Standards, testing, and certification for geothermal PE pipe
- Investment structure and relative cost planning
- Service, support, and turnkey delivery from Faygo
- Frequently asked questions
- Talk to Faygo about your geothermal pipe line
How a Ground Source Heat Pump Loop Works and Where the Pipe Sits
A ground source heat pump moves heat between a building and the earth using a closed circuit of buried pipe filled with water or an antifreeze solution. In winter the ground is warmer than the outdoor air, so the circulating fluid absorbs low-grade heat from the soil or rock and carries it to the heat pump, which raises the temperature and delivers it to radiators, fan coils, or floor heating circuits. In summer the direction reverses and the same buried loop rejects heat from the building into the ground. Because the earth below a few meters holds a nearly constant temperature year round, the heat pump works against a far smaller temperature difference than an air source machine, which is the entire reason geothermal central heating achieves high seasonal efficiency in cold climates.
The buried pipe network is called the ground loop, ground heat exchanger, or ground array, and it takes one of four common forms. Each form places different demands on the pipe and therefore on the extrusion equipment that produced it.
Vertical borehole loops. Boreholes are drilled from roughly 60 to 200 meters deep, and a U-bend assembly made from two pipe legs joined by a factory-molded elbow is lowered into each hole. The annulus is then filled with thermally enhanced grout. Vertical fields are the dominant choice for geothermal central heating pipeline engineering in cities because they need very little surface area. Typical U-bend legs use 25 mm, 32 mm, or 40 mm PE100 pipe, and the pipe must be supplied in continuous coils long enough to reach the bottom of the hole and back without a joint. A buried fusion joint inside a grouted borehole is a risk no designer accepts, so coil length and coil quality are hard requirements.
Horizontal trench loops. Where land is available, pipe is laid in trenches 1.2 to 2.5 meters deep, either as straight parallel runs or as overlapping slinky coils. Horizontal arrays typically use 25 mm to 40 mm pipe and consume more total length than a vertical field for the same capacity, but drilling cost disappears. The pipe sees more thermal cycling here because shallow soil temperature swings with the seasons, so resistance to slow crack growth matters.
Pond and lake loops. Coiled pipe bundles are sunk into a body of water and anchored below the freeze line. Water contact is continuous, so long-term hydrolytic stability and resistance to biological fouling are the governing properties.
Header and distribution mains. Individual boreholes or trenches connect through horizontal runouts to a header manifold, then to a supply and return main that enters the mechanical room. Headers and mains carry the combined flow and step up in diameter, commonly 63 mm, 90 mm, 110 mm, 125 mm, or 160 mm for a district-scale field. These sizes are produced in straight lengths on a line equipped with a cutter and tilting table rather than a coiler.
A complete geothermal central heating project therefore needs a pipe supply that spans coiled small diameters and straight large diameters. Producers who serve this market usually run one line configured for 16 mm to 63 mm with a dual coiler and a second line configured for 63 mm to 160 mm with a planetary cutter, which is exactly how Faygo configures its PE pipe extrusion systems for geothermal customers.
Why Polyethylene Resists Corrosion Underground
Polyethylene resists corrosion because it is chemically inert, non-metallic, and non-conductive, so the electrochemical reactions that destroy buried metal pipe simply cannot start. Steel corrodes when an anode, a cathode, an electrolyte, and a return path exist together; soil moisture provides the electrolyte and the metal provides the rest. PE has no free electrons to donate, does not form a galvanic couple with adjacent metals, does not scale, does not tuberculate, and is not attacked by the sulfates, chlorides, or mildly acidic groundwater that shorten the life of carbon steel and ductile iron in the same trench. For a ground loop that must survive decades of continuous burial, that immunity is the deciding property.
Several distinct mechanisms combine to give a correctly produced PE ground loop its long service life.
Chemical inertness across the soil pH range. PE is unaffected by soil pH from strongly acidic to strongly alkaline, and it resists salts, dilute acids, alkalis, and the antifreeze solutions circulated inside the loop. Propylene glycol, ethylene glycol, and methanol-based heat transfer fluids are all compatible with polyethylene at ground loop operating temperatures, which is not true of every polymer.
No galvanic or stray-current corrosion. Because PE is an electrical insulator, a polyethylene ground loop cannot act as an unintended current path near rail lines, cathodic protection systems, or grounding electrodes. Metal loops in the same environment need isolation fittings and monitoring; PE loops need neither.
Resistance to slow crack growth. The failure mode that actually threatens a buried PE pipe is not corrosion but slow crack growth initiated at a scratch, a rock point load, or a poorly fused joint. Modern PE100 resins are engineered with bimodal molecular weight distribution specifically to resist this, and pipe produced with clean melt, correct cooling, and low residual stress carries far more crack resistance margin than pipe extruded with an overheated barrel or an unbalanced cooling tank. Equipment quality is directly connected to long-term crack resistance, which is a point many buyers overlook.
Oxidation and antioxidant protection. PE compounds contain antioxidant packages that protect the polymer during processing and service. Excessive melt temperature, long residence time in the barrel, or shear peaks consume that antioxidant reserve before the pipe is even installed. Oxidation induction time testing on finished pipe is the standard way to confirm that the extrusion process preserved the stabilizer system, and a line with accurate temperature control and a properly designed screw protects that reserve.
Carbon black and buried UV exposure. Ground loop pipe is normally black, pigmented with roughly 2 to 2.5 percent finely dispersed carbon black, which protects the pipe during above-ground storage before installation. Dispersion quality matters as much as loading, and poor dispersion shows up as gray streaking on the pipe wall. Good mixing in the plasticizing section is what delivers even color and even protection.
Abrasion and scaling behavior. Because the bore stays smooth and no oxide layer builds up, the hydraulic roughness of a PE ground loop does not increase over time. A metal loop’s pumping energy climbs as scale accumulates; a PE loop’s does not. Over a thirty-year district heating operation, that stable pumping demand is a real operating advantage, not a marketing claim.
The combination of these properties is why PE100 ground loop pipe is commonly rated for a 50-year design service life at its stated pressure class and reference temperature, and why geothermal designers treat the buried array as a permanent civil asset rather than a serviceable mechanical component.
PE100, PE80, PE-RT and PEX for Geothermal Loops
The four polymer families used in ground source heat pump loops differ mainly in pressure rating, temperature capability, flexibility, and how they are joined. Choosing among them is a design decision, but it is also a production decision, because each material needs a slightly different screw, temperature profile, and cooling strategy on the extrusion line.
PE100 is the workhorse of geothermal central heating. It is a bimodal high-density polyethylene with a minimum required strength of 10 MPa, giving high pressure capability at a given wall thickness and excellent resistance to slow crack growth. Vertical U-bends, horizontal arrays, headers, and mains are predominantly PE100. It is joined by butt fusion and electrofusion, both of which create a joint as strong as the pipe wall.
PE80 has a minimum required strength of 8 MPa and remains common in smaller diameters and in markets where legacy specifications persist. For the same pressure class it needs a thicker wall than PE100, which raises material consumption but also slightly increases stiffness. PE80 processes at a marginally lower melt temperature and is a little more forgiving on the cooling tank.
PE-RT, polyethylene of raised temperature resistance, uses a controlled comonomer distribution to hold pressure at elevated temperature without crosslinking. Its practical advantages for geothermal work are flexibility at small diameters and the fact that it can still be heat fused, unlike crosslinked material. PE-RT is the usual choice for 16 mm to 32 mm distribution circuits, floor heating loops fed by the heat pump, and the indoor side of a geothermal central heating system.
PEX, crosslinked polyethylene, offers the highest continuous temperature capability of the four, but crosslinking makes it impossible to butt fuse; it relies on mechanical or compression fittings. That is acceptable indoors and unacceptable inside a grouted borehole, so PEX appears on the building side rather than in the buried array.
The table below summarizes the properties that matter when specifying pipe for a ground source heat pump project. Values are typical published ranges for pipe-grade compounds and will vary by grade and supplier.
| Property | PE100 | PE80 | PE-RT Type II | PEX-a/b |
|---|---|---|---|---|
| Minimum required strength | 10.0 MPa | 8.0 MPa | Rated by temperature class | Rated by temperature class |
| Density | 0.949 to 0.960 g/cm3 | 0.940 to 0.950 g/cm3 | 0.933 to 0.945 g/cm3 | 0.938 to 0.947 g/cm3 |
| Melt flow rate, 190 C / 5 kg | 0.2 to 0.5 g/10 min | 0.4 to 0.9 g/10 min | 0.5 to 1.2 g/10 min | Base resin dependent |
| Thermal conductivity | 0.40 to 0.45 W/m·K | 0.38 to 0.43 W/m·K | 0.38 to 0.42 W/m·K | 0.38 to 0.41 W/m·K |
| Continuous service temperature | Up to 40 C at full rating | Up to 40 C at full rating | Up to 70 C with derating | Up to 95 C with derating |
| Heat fusion joinable | Yes, butt and electrofusion | Yes, butt and electrofusion | Yes, socket and electrofusion | No, mechanical fittings only |
| Flexibility at 25 mm | Medium | Medium to high | High | High |
| Typical geothermal use | Vertical U-bends, headers, mains | Small horizontal loops | Distribution and floor circuits | Indoor building side only |
| Design service life reference | 50 years at rated class | 50 years at rated class | 50 years at class condition | 50 years at class condition |
One practical note on thermal conductivity: polyethylene is a poor conductor compared with metal, and no polymer choice will change that meaningfully. Ground loop heat transfer is governed far more by borehole grout conductivity, soil or rock conductivity, flow regime inside the pipe, and total loop length than by the pipe polymer itself. What the pipe must deliver is dimensional consistency, pressure integrity, and thin, uniform walls at the specified standard dimension ratio, because a thinner uniform wall lowers thermal resistance and a thicker uneven wall raises it. That is a manufacturing outcome, and it is decided by the extrusion line.
Anatomy of a PE Ground Source Heat Pump Pipe Extrusion Line
A PE ground source heat pump pipe extrusion line is a continuous process train in which molten polyethylene leaves a die as a tube, is fixed to final diameter under vacuum, is cooled through a controlled temperature gradient, is pulled at constant speed, and is then cut or coiled. Every station influences the finished pipe, and a weakness anywhere shows up as ovality, wall variation, internal stress, or a pipe that fails hydrostatic testing. Understanding the train section by section is the fastest way to evaluate a supplier’s proposal.
Raw material handling and drying. PE pellets arrive with low moisture, but geothermal pipe producers who blend in regrind or who store material in humid conditions still install a hopper dryer or dehumidifying dryer. A vacuum loader feeds the hopper, and a gravimetric or volumetric metering unit doses masterbatch if color is added at the machine rather than bought pre-compounded. Consistent feeding is the first requirement for consistent wall thickness.
Single-screw extruder. Polyethylene pipe is extruded on a grooved-feed single-screw extruder with a barrier screw and a mixing section. Grooved feed bushings raise output and stabilize throughput against pressure fluctuation, which is exactly what a pipe line needs. Typical L/D ratios run from 30:1 to 38:1 for PE, long enough to plasticize fully at moderate melt temperature. The barrel is zoned, usually four to seven heating zones with air or water cooling, and the screw is designed to melt the polymer through conducted and shear heat without creating hot spots that would consume the antioxidant package. Screw diameter is the main sizing variable: a 45 mm screw suits small coiled pipe, 65 mm covers the mid range, and 90 mm or larger serves header and main diameters.
Screen changer and melt pump. A hydraulic screen changer removes contaminants and unmelted particles, and on high-specification lines a melt gear pump smooths pressure pulsation so the die sees a constant flow. For geothermal pipe, where wall uniformity translates directly into thermal and pressure performance, a melt pump is a worthwhile option rather than a luxury.
Spiral die head. The die head converts the melt stream into an annular tube. Modern PE pipe dies use a spiral mandrel design that distributes flow around the circumference and eliminates the weld lines that a simple spider die leaves behind. Weld lines are weak planes and are unacceptable in a pipe that must resist slow crack growth for decades. The die also incorporates a basket or streamlined flow path to minimize residence time. Die and mandrel sets are changed to move between diameters, and a well-planned line uses a common die body with interchangeable tooling to keep changeover time short.
Vacuum calibration tank. Immediately after the die the soft tube enters a vacuum calibration tank. A calibration sleeve sized to the outside diameter holds the pipe while vacuum draws the wall against the sleeve and water sprays cool the surface. The vacuum level, typically a fraction of an atmosphere and adjusted by valve, is what fixes outside diameter and roundness. Tank length depends on wall thickness and line speed; small coiled pipe may need a single 3 meter tank while a 160 mm header pipe needs a longer first tank plus additional cooling.
Spray cooling tanks. After calibration, one or more spray cooling tanks remove the remaining heat. Spray cooling is preferred over full immersion for thick walls because it can be staged: the first tank runs cooler to freeze the outer skin, later tanks run warmer so the inner wall cools gradually. Cooling too fast on the outside while the inside is still molten locks in residual stress, and residual stress is a direct enemy of long-term crack resistance. A chiller supplies the water circuit, and water temperature is a controlled process parameter, not an afterthought.
Haul-off unit. A caterpillar haul-off with two, three, four, six, or eight tracks pulls the pipe at precisely regulated speed. Haul-off speed together with extruder output sets the wall thickness: faster haul-off with the same output gives a thinner wall. The drive is servo or inverter controlled and synchronized with the extruder so that a change in one is compensated in the other. Track pressure must be firm enough to prevent slip and gentle enough to avoid marking the pipe.
Cutting or coiling. This is the branch point that decides how a geothermal line is configured. Straight lengths for headers and mains use a planetary saw or chipless cutter that travels with the pipe while cutting, followed by a tilting discharge table. Coiled small-diameter pipe for vertical U-bends and horizontal arrays uses a single or dual coiler with automatic length counting and strapping. Because a vertical borehole demands one continuous coil long enough for the full down-and-back run, coiler capacity and coil tension control are critical purchasing criteria for geothermal producers.
Marking, testing, and control. An inkjet or laser printer marks the pipe with size, class, standard, and a meter counter. Online ultrasonic wall thickness measurement is available for producers who need continuous documentation. The whole train runs under a PLC with an HMI touch screen, allowing recipes to be stored per pipe size, parameters to be adjusted in real time, and production data to be logged. Faygo builds its lines with an intelligent control system and internationally recognized brand electrical components, and each line is proven with 72 hours of continuous operation before delivery.
Faygo PE Pipe Extrusion Line: Specifications and Configurations
Faygo builds PE ground source heat pump pipe extrusion lines as configuration classes rather than fixed catalog boxes, sized around the diameter band and output a customer actually needs. The three classes below cover the great majority of geothermal pipe programs, from a small workshop producing 25 mm and 32 mm U-bend coils to a plant supplying district-scale headers. Faygo’s overall pipe extrusion capability spans 12 mm to 575 mm in PE, PP, and PVC, so a producer who later adds drainage, gas, or irrigation pipe can stay within the same equipment platform.
| Parameter | Coil line, 16 to 63 mm | Standard line, 20 to 110 mm | Header line, 63 to 160 mm |
|---|---|---|---|
| Pipe outside diameter range | 16 to 63 mm | 20 to 110 mm | 63 to 160 mm |
| Wall thickness range | 1.8 to 6.0 mm | 2.0 to 10.0 mm | 4.0 to 15.0 mm |
| Material | PE100, PE80, PE-RT | PE100, PE80, PE-RT, PP | PE100, PE80 |
| Extruder screw diameter | 45 or 50 mm | 65 mm | 75 or 90 mm |
| Screw L/D ratio | 33:1 | 33:1 to 36:1 | 36:1 to 38:1 |
| Feed system | Grooved feed, water cooled | Grooved feed, water cooled | Grooved feed, water cooled |
| Maximum output | 120 to 180 kg/h | 250 to 350 kg/h | 400 to 600 kg/h |
| Typical line speed | 8 to 30 m/min | 3 to 18 m/min | 1 to 8 m/min |
| Die head type | Spiral mandrel, quick change | Spiral mandrel, basket type | Spiral mandrel, basket type |
| Vacuum calibration tank | 1 tank, 3 to 4 m | 1 tank, 6 m | 1 tank, 6 m plus stainless inner |
| Spray cooling tanks | 1 tank, 4 to 6 m | 1 to 2 tanks, 6 m each | 2 to 3 tanks, 6 m each |
| Haul-off | 2 or 3 track caterpillar | 4 track caterpillar | 4 or 6 track caterpillar |
| Downstream end | Single or dual coiler | Planetary cutter plus coiler option | Planetary saw and tilting table |
| Installed power | 75 to 110 kW | 130 to 180 kW | 200 to 280 kW |
| Control | PLC and HMI, recipe storage | PLC and HMI, inverter drives | PLC and HMI, servo haul-off, data logging |
| Pre-delivery testing | 72-hour continuous run | 72-hour continuous run | 72-hour continuous run |
| Certification | CE, ISO | CE, ISO | CE, ISO |
Installed power in the table is the connected load, not the running load. A PE pipe line typically draws between 55 and 70 percent of connected power in steady production, because barrel heaters cycle off once the process reaches equilibrium and the extruder motor operates below rated torque. Buyers planning a transformer or a workshop electrical design should ask Faygo for both figures; the factory’s consulting service includes water and electricity design and 3D workshop layout precisely so that these numbers are settled before the machine arrives.
Two configuration decisions deserve extra attention for geothermal producers. The first is the coiler. A vertical borehole 150 meters deep needs a U-bend coil longer than 310 meters, and a coiler that cannot hold and tension that length forces the producer to make joints, which the specification forbids. Faygo sizes the coiler around the deepest borehole the customer expects to serve. The second is the number of cooling tanks. Header pipe at 160 mm with a 15 mm wall carries enormous stored heat, and short-changing the cooling section leads to pipe that appears round at the haul-off and goes oval on the storage rack.
Process Parameters and Dimensional Quality Control
Producing geothermal-grade PE pipe is less about running fast and more about running stable. The core discipline is holding melt temperature, vacuum, cooling water temperature, and haul-off speed steady so that outside diameter, wall thickness, and ovality stay inside tolerance for the entire shift. The table below gives working parameter windows for PE100 pipe on a Faygo line. Treat them as starting points to be optimized against the specific resin grade and pipe size.
| Parameter | Typical setting | Effect if too low | Effect if too high |
|---|---|---|---|
| Barrel zone 1 (feed) | 160 to 175 C | Unmelted pellets, surging | Early melting, feed slip |
| Barrel middle zones | 180 to 200 C | High motor load, poor mixing | Antioxidant consumption |
| Die head zones | 195 to 215 C | Rough bore, melt fracture | Sagging, thin top wall |
| Melt temperature at die | 200 to 215 C | Poor weld healing, low gloss | Degradation, low oxidation induction time |
| Melt pressure | 18 to 32 MPa | Output surging | Screw and gearbox stress |
| Screw speed | 30 to 85 rpm by size | Output below target | Shear heat, melt temperature rise |
| Vacuum in calibration tank | 0.02 to 0.06 MPa negative | Undersize, oval pipe | Sleeve marking, pipe sticking |
| Calibration water temperature | 14 to 20 C | Frozen skin, residual stress | Soft pipe, dimension drift |
| Final cooling water temperature | 18 to 25 C | Stress locked in wall | Pipe still warm at coiler |
| Haul-off speed tolerance | Within 0.5 percent of setpoint | Thick wall, material waste | Thin wall, pressure class failure |
| Outside diameter tolerance | Per standard grade B or better | Fusion fit-up problems | Fitting interference |
| Ovality after coiling | Within standard limit for coil | Not applicable | Rejected at fusion, re-rounding needed |
Wall thickness is controlled by the ratio of extruder output to haul-off speed, and the practical technique is to fix the haul-off speed at the value that gives the target meters per hour, then trim screw speed until the measured wall sits just above the minimum. Running with a deliberate positive margin of five to eight percent above minimum wall is normal practice, because the standard permits no point below minimum. Producers with online ultrasonic measurement can shrink that margin and save resin, which over a year of continuous production is one of the largest cost reductions available to a pipe plant.
Ovality deserves separate discussion for geothermal work because so much of the pipe ships in coils. A coiled pipe naturally flattens slightly at the bend, and standards allow more ovality for coiled pipe than for straight lengths. Even so, a badly oval pipe cannot be aligned in a butt fusion machine or seated in an electrofusion coupler without a re-rounding clamp. The way to keep coil ovality low is to cool the pipe fully before it reaches the coiler, keep coil diameter generous relative to pipe diameter, and control coiling tension so the pipe is laid rather than dragged.
Three further quality checks belong in any geothermal pipe plant routine. Melt flow rate testing on incoming resin and on finished pipe confirms that processing did not degrade the polymer, with a change of more than about 20 percent flagged for investigation. Oxidation induction time testing confirms that the antioxidant package survived. Hydrostatic pressure testing at the temperatures and stress levels required by the applicable pipe standard confirms long-term integrity. A producer who runs these three tests consistently can defend a 50-year service claim; a producer who runs none of them cannot.
Faygo PE-RT and PP-R Pipe Extrusion Line for Small-Diameter Circuits
Geothermal central heating does not stop at the borehole. Once the ground loop delivers heat to the heat pump, the building side needs its own pipe network, and that network is dominated by PE-RT and PP-R in diameters from 16 mm to 32 mm for floor heating circuits and 20 mm to 160 mm for risers and distribution. Producers who already supply ground loop pipe frequently add this second line because it sells into the same project and often to the same customer. Faygo’s PP-R and PE-RT pipe extrusion line covers PP-R and PE pipe from 16 mm to 160 mm and PE-RT pipe from 16 mm to 32 mm, which maps precisely onto the indoor side of a ground source heat pump installation.
Technically the line resembles the ground loop line but differs in three ways. PE-RT and PP-R run at different melt temperatures and need screw geometries matched to their rheology, PP-R in particular requiring gentler shear and a longer cooling section because of its slower crystallization. Small-diameter circuits run at much higher line speeds, so the coiler and length counter work harder than the extruder. And oxygen barrier construction is common on the building side, which means the line may be extended with a co-extrusion head and adhesive layer stations to apply an ethylene vinyl alcohol barrier that keeps dissolved oxygen out of the heat pump circuit and protects steel components from corrosion.
| Parameter | PE-RT floor circuit line | PP-R and PE-RT general line | Barrier co-extrusion line |
|---|---|---|---|
| Pipe outside diameter | 16 to 32 mm | 16 to 110 mm | 16 to 32 mm |
| Material | PE-RT Type I and II | PP-R, PE-RT, PE | PE-RT with barrier layer |
| Wall thickness | 1.8 to 3.0 mm | 2.0 to 12.5 mm | 2.0 to 3.0 mm plus barrier |
| Main extruder screw | 45 mm, L/D 30:1 | 65 mm, L/D 33:1 | 45 mm, L/D 30:1 |
| Co-extruder | Optional 20 mm stripe unit | Optional 25 mm stripe unit | Two units, 20 and 25 mm |
| Output | 80 to 130 kg/h | 200 to 320 kg/h | 70 to 110 kg/h |
| Line speed | 15 to 40 m/min | 2 to 20 m/min | 12 to 30 m/min |
| Melt temperature window | 195 to 215 C | 200 to 230 C by material | 195 to 215 C main layer |
| Calibration and cooling | Vacuum tank 4 m plus spray 4 m | Vacuum tank 6 m plus spray 6 m | Vacuum tank 4 m plus spray 6 m |
| Haul-off | 2 track, servo | 4 track, servo | 2 track, servo |
| Downstream | Dual coiler, auto changeover | Cutter plus coiler option | Dual coiler with tension control |
| Installed power | 60 to 85 kW | 120 to 165 kW | 75 to 100 kW |
| Control and testing | PLC and HMI, 72-hour test | PLC and HMI, 72-hour test | PLC and HMI, 72-hour test |
| Certification | CE, ISO | CE, ISO | CE, ISO |
Faygo’s broader pipe and profile portfolio gives geothermal producers useful adjacent options. The PE, PP, and PVC single wall corrugated pipe extrusion line covers 6 mm to 200 mm and produces the flexible conduit used to sleeve and protect ground loop runouts where they pass under slabs or through building entries. The PVC pipe production line handles UPVC pipe in large diameters and varied wall thickness for drainage and site works, and the PVC double pipe extrusion line produces two 16 mm to 40 mm pipes simultaneously for conduit and small services. Within the Wanplas group, matched auxiliary and compounding equipment is available so that a pipe plant can source mixing, drying, and material handling systems from the same brand relationship rather than assembling a supply chain from scratch.
Joining Methods, Loop Assembly, and Pressure Testing
A ground loop is only as reliable as its joints, and the joining method is chosen before the pipe is even ordered because it constrains material, wall thickness, and dimensional tolerance. Three heat fusion techniques dominate geothermal work, plus a small role for mechanical fittings above ground.
Butt fusion heats the squared ends of two pipes against a heater plate, removes the plate, and forces the melted faces together under controlled pressure until they cool. Done correctly, the joint is homogeneous and as strong as the pipe. Butt fusion is standard for headers and mains from 63 mm upward and requires pipe with tight outside diameter tolerance and low ovality so the ends align within the clamp. Buried butt fusion joints in a header trench are entirely normal practice.
Socket fusion heats the pipe outside surface and the fitting inside surface simultaneously, then pushes them together. It is common for smaller diameters and for PP-R and PE-RT building circuits, and it is quick, but the socket depth and the operator’s technique determine joint quality, so it is used less in critical buried applications than electrofusion.
Electrofusion uses a fitting with an embedded resistance wire; a control unit passes current, the wire melts the interface, and the joint solidifies. Electrofusion is preferred for tight trenches, repair work, and any location where a butt fusion machine cannot be aligned. It also produces the most consistently documented joint because modern control units log voltage, current, time, and fitting barcode for every fusion. For district-scale geothermal central heating pipeline engineering, that traceability is often written into the contract.
Factory U-bends. The bottom of a vertical borehole uses a molded U-bend rather than a field joint. These are injection molded or butt fused in the factory under controlled conditions and pressure tested before shipment. Fusing a U-bend in the field, then grouting it 150 meters underground, is a risk no serious installer takes.
Assembly of a vertical field then follows a fixed sequence. The U-bend assembly is pressure tested on the drum before it goes down the hole, lowered with a weight to overcome buoyancy, pressure tested again once at depth, grouted with a thermally enhanced bentonite or cement grout placed from the bottom up through a tremie pipe, and pressure tested a third time after grouting. The horizontal runouts are then fused to the loop legs, the header manifold is assembled, and the complete circuit is flushed, purged of air, filled with the heat transfer fluid, and pressure tested as a system. Purging matters more than most people expect: a single trapped air pocket at a high point can throttle flow in an entire circuit and quietly cut system efficiency for years.
Pressure testing practice for ground loops normally applies a test pressure well above working pressure and holds it for a defined period with temperature compensation, because polyethylene creeps and a pressure drop caused by pipe expansion can be mistaken for a leak. Experienced crews run a two-stage test, allowing the initial relaxation before starting the timed hold. All of this presumes pipe that meets its dimensional standard, which brings the discussion back to the extrusion line: pipe with excessive ovality, wall variation, or internal stress makes every joint harder and every test more likely to fail.
Thermal Performance and Loop Field Design
Ground loop thermal performance is governed by a chain of resistances between the circulating fluid and the undisturbed ground, and pipe is only one link. Understanding the whole chain explains why pipe wall uniformity matters and why chasing exotic pipe materials rarely pays.
The chain runs as follows: convective resistance from the fluid to the pipe bore, conductive resistance through the pipe wall, contact and conductive resistance through the grout or backfill, and finally conductive resistance through the soil or rock to the far field. In a typical grouted vertical borehole the grout and ground dominate, the pipe wall contributes a modest share, and the fluid film contributes a share that the designer directly controls through flow rate.
Flow regime. Turbulent flow inside the pipe collapses the fluid film resistance, so ground loops are designed for turbulent conditions, generally by keeping the flow rate above a threshold that depends on pipe diameter, fluid viscosity, and temperature. Antifreeze raises viscosity and pushes the turbulence threshold higher, which is why glycol loops need slightly more pumping than plain water loops. Oversized pipe reduces pressure drop but risks dropping into laminar flow, which quietly ruins heat transfer. Undersized pipe guarantees turbulence but burns pumping energy. Correct sizing sits between the two.
Wall thickness and standard dimension ratio. A thinner wall gives lower conductive resistance, so designers prefer the highest standard dimension ratio that still satisfies the pressure requirement, commonly SDR 11 or SDR 17 for ground loops depending on borehole depth and system pressure. Deep boreholes create static head that pushes toward SDR 11. This is also where manufacturing quality shows: if a pipe is nominally SDR 11 but the wall varies around the circumference, the thick side adds resistance while the thin side sets the pressure rating, and the producer pays twice.
Grout conductivity. Thermally enhanced grouts substantially outperform plain bentonite, and specifying the grout is usually a higher-leverage decision than any pipe choice. Poorly placed grout that leaves voids is worse still, because air is an excellent insulator.
Loop length. Required loop length per unit of heating or cooling capacity varies widely with ground conductivity, undisturbed ground temperature, borehole spacing, and the annual balance between heat extraction and rejection. Wet, conductive rock needs far less borehole than dry sand. Because a district geothermal field runs for decades, designers also check the long-term thermal balance; a heating-dominated field slowly cools the ground over many years if boreholes are packed too closely, and the fix is wider spacing, more length, or a supplementary heat rejection source.
Pipe surface and fouling. Because polyethylene does not corrode or scale, the bore stays smooth for the life of the loop and design pressure drop remains valid decades later. Systems built with metal loops need a fouling allowance from day one.
For a pipe producer, the practical takeaway is that geothermal customers evaluate pipe on dimensional consistency, pressure class, fusion behavior, coil length, and documentation, not on marginal thermal conductivity claims. An extrusion line that reliably produces round pipe with even walls in long clean coils is what wins repeat district heating supply contracts.
PE Ground Loop Pipe Compared With Metal and Composite Options
Polyethylene became the default ground loop material because every alternative fails on at least one of the four criteria that matter underground: corrosion resistance, joint reliability, installed cost, and service life. The comparison below is between material technologies, evaluated on the criteria a geothermal designer actually weighs.
| Criterion | PE100 polyethylene | Carbon steel | Copper | Multilayer composite |
|---|---|---|---|---|
| Corrosion in soil | Immune | High risk, needs coating and cathodic protection | Pitting risk in acidic or saline soil | Outer layer resistant, joints vulnerable |
| Buried joint reliability | Fused, homogeneous | Welded, coating repair required | Brazed, corrosion-prone | Press or compression, not preferred buried |
| Thermal conductivity of wall | Low, offset by thin wall | High | Very high | Medium |
| Long coil availability | Yes, hundreds of meters | No | Limited | Yes, shorter lengths |
| Installation labor | Low | Very high | High | Medium |
| Scaling and fouling over time | None | Significant | Moderate | Low |
| Stray current sensitivity | None, insulator | High | High | Low to medium |
| Relative material cost | Low | Medium | Very High | High |
| Relative installed cost | Low | Very High | Premium | High |
| Suitability for grouted borehole | Standard practice | Not used | Rare, direct exchange systems only | Not standard |
The apparent weakness of polyethylene, its low wall conductivity, turns out to matter far less than intuition suggests, because the pipe wall is thin and the borehole and ground resistances dominate the total. Meanwhile the advantages compound: a fused PE loop has no joints that corrode, no coating to damage during backfill, no cathodic protection to monitor, and no scale to reduce flow. That is why the market converged on PE and why the equipment question for a producer is not whether to make PE ground loop pipe but which line configuration to buy.
Selection Guide: Matching Your Pipe Program to a Faygo Line
Choosing an extrusion line starts with the pipe program, not the machine catalog. Define the diameter range you must supply, the deepest borehole your market drills, whether you sell coils or straight lengths, and the annual tonnage you need, and the correct configuration falls out almost automatically. The table below maps common geothermal pipe programs to a Faygo line configuration.
| Your requirement | Loop type served | Diameter and material | Recommended Faygo line | Key options to add |
|---|---|---|---|---|
| Start-up plant, U-bend coils only | Vertical borehole loops | 25 to 40 mm PE100 | Coil line, 16 to 63 mm, 45 mm screw | Long-length single coiler, meter counter |
| Mixed coil program with high uptime | Vertical and horizontal arrays | 20 to 63 mm PE100 and PE80 | Coil line, 16 to 63 mm, 50 mm screw | Dual coiler with automatic changeover |
| Contractor supply, coils plus short mains | Loops plus runouts | 20 to 110 mm PE100 | Standard line, 20 to 110 mm, 65 mm screw | Planetary cutter plus coiler branch |
| District heating header supply | Manifolds, supply and return mains | 63 to 160 mm PE100 | Header line, 63 to 160 mm, 75 or 90 mm screw | Extra spray tank, melt pump, tilting table |
| Building-side circuits for heat pumps | Floor heating and distribution | 16 to 32 mm PE-RT | PE-RT floor circuit line | Dual coiler, color stripe co-extruder |
| Oxygen barrier pipe requirement | Closed circuits with steel components | 16 to 32 mm PE-RT with barrier | Barrier co-extrusion line | Adhesive and barrier extruders, tension control |
| Full geothermal package supplier | Ground array plus building side | 16 to 160 mm PE100 and PE-RT | Two lines: coil line plus header line | Shared chiller, central feeding, layout design |
| Protective conduit for runouts | Slab and entry penetrations | 6 to 200 mm PE, PP or PVC | Single wall corrugated pipe extrusion line | Forming block sets by size |
| Site drainage and civil works pipe | Trench and surface drainage | UPVC large diameter | PVC pipe production line | Belling machine, socket tooling |
Two questions decide most of the remaining detail. First, what is your realistic annual tonnage? A single coil line running two shifts at 150 kg/h produces roughly 1,700 to 1,900 tonnes per year at reasonable utilization, which is enough to supply a substantial regional geothermal market. If your forecast exceeds that, a second line beats pushing one line past its stable window. Second, how often will you change size? Frequent changeover favors quick-change die tooling and stored recipes; a stable single-size program favors optimizing for maximum output on that one size.
Application Industries and Geothermal Project Types
Anti-corrosion PE ground source heat pump pipe reaches the market through several distinct industries, and a producer who understands them can position product and capacity intelligently. Faygo’s pipe extrusion equipment already serves construction, municipal engineering, agricultural irrigation, and communication and power sectors, and geothermal central heating sits at the intersection of the first two.
Construction and building services. Residential towers, commercial offices, hotels, schools, and hospitals install ground source heat pump systems to meet energy codes and reduce operating cost. Each project consumes ground loop coils, header pipe, runout pipe, and the building-side PE-RT distribution and floor heating circuits. Construction customers value delivery reliability and documentation as much as price, because a delayed pipe shipment stalls a drilling crew that is charging by the day.
Municipal and district energy engineering. Municipal geothermal central heating pipeline engineering is the largest single consumer of loop pipe. A district system serving a residential district or a campus can install hundreds of boreholes and kilometers of header main. These projects are tendered, specification-driven, and traceability-heavy: batch records, test certificates, and material declarations are typically required. Municipal work also pulls in large-diameter distribution pipe, which is why producers eventually add a header line covering 110 mm to 160 mm and beyond.
Geothermal, HVAC, and mechanical contracting. Specialist geothermal drillers and mechanical contractors buy pre-assembled U-bend coils, headers, fusion fittings, and manifolds. This channel rewards a producer who can supply consistent coil lengths, clean printing, and pipe that fuses without argument. Contractors talk to each other, and a reputation for pipe that passes pressure tests the first time is worth more than a discount.
Agriculture and horticulture. Greenhouses use ground source heat pumps for climate control, and agricultural sites often have the land for horizontal loop fields. The same producers usually also supply PE drip irrigation and sprinkler pipe, which runs on the same extrusion line with different tooling. Faygo’s agricultural irrigation solutions and its geothermal pipe capability therefore share equipment, and one line can serve both markets across the season.
Industrial and process facilities. Data centers, food plants, and light manufacturing sites use ground loops for base-load cooling and heat recovery. These installations tend toward larger diameters, higher pressure classes, and stricter documentation, and they frequently combine a geothermal array with other heat sources.
Retrofit of existing heating networks. An increasingly common project type replaces or supplements a conventional boiler plant serving an existing building group with a ground source system, reusing the existing indoor distribution while adding a new buried array. Retrofit work is diameter-diverse and schedule-driven, favoring suppliers who hold stock across sizes.
Standards, Testing, and Certification for Geothermal PE Pipe
Geothermal PE pipe is normally produced to the same standards as pressure water pipe, with project specifications adding ground loop requirements on top. Knowing which document governs a market determines the tooling, the tolerance class, and the test regime a producer must support.
| Reference | Scope | What it controls in production |
|---|---|---|
| ISO 4427 | PE pipes and fittings for water supply | Dimensions, tolerance grades, pressure classes, material designation |
| ISO 12162 | Classification of thermoplastic materials by MRS | PE80 and PE100 designation basis |
| ISO 1167 | Internal pressure resistance test | Hydrostatic hold tests at defined stress and temperature |
| ISO 1133 | Melt mass-flow rate determination | Confirms resin was not degraded during extrusion |
| ISO 11357 | Differential scanning calorimetry | Oxidation induction time, antioxidant reserve |
| ISO 13479 | Notched pipe test | Resistance to slow crack growth |
| ISO 22391 | PE-RT piping systems for hot and cold water | PE-RT classes, dimensions, and performance |
| ASTM D3035 and ASTM F714 | PE pipe by controlled outside diameter | Dimension ratio system used in North American projects |
| ASTM D2513 and ASTM F2620 | PE piping and heat fusion practice | Fusion procedures qualification for buried joints |
| GB/T 13663 | PE pipes for water supply in China | Domestic dimensional and performance requirements |
| CE marking | Machinery safety in the European market | Guarding, electrical safety, documentation of the line |
| ISO 9001 | Quality management system | Traceability, inspection records, corrective action |
Faygo equipment is CE and ISO certified, which addresses the machinery side of compliance. The pipe side belongs to the producer, but the equipment determines whether compliance is easy or a daily fight. Accurate temperature control protects oxidation induction time. A spiral die without weld lines protects notched pipe test performance. Precise haul-off control protects wall thickness and therefore pressure class. Adequate cooling protects ovality and residual stress. Buyers should read a machine specification as a list of the quality outcomes it enables, not as a list of components.
Documentation practice completes the picture. A geothermal pipe batch record should tie the resin lot, the production date and shift, the line and recipe, the measured dimensions, and the test results into one traceable package. District heating clients increasingly ask for this at tender stage, and producers who already have the discipline win work that price-only competitors cannot reach.
Investment Structure and Relative Cost Planning
Equipment budgets for a PE ground source heat pump pipe plant break into machinery, utilities, tooling, plant works, and working capital. Because prices move with specification, currency, and market conditions, the table below expresses each element on a relative scale rather than an absolute figure, so the structure stays valid regardless of when it is read.
| Investment element | Relative cost level | Notes for planning |
|---|---|---|
| Coil line, 16 to 63 mm | Medium | Entry point for a geothermal pipe producer |
| Standard line, 20 to 110 mm | High | Widest market coverage per unit invested |
| Header line, 63 to 160 mm | Very High | Needed for district-scale mains supply |
| Barrier co-extrusion upgrade | Medium | Adds two extruders and a layered die |
| Additional die and calibration tooling per size | Low to Medium | Budget one set per diameter you will sell |
| Long-length coiler with tension control | Medium | Essential for deep borehole U-bend coils |
| Online ultrasonic wall measurement | Medium | Pays back through reduced resin overuse |
| Melt gear pump | Low to Medium | Improves wall uniformity on thick-wall pipe |
| Chiller, cooling tower, compressed air | Medium | Size for peak line load plus reserve |
| Transformer and electrical distribution | Medium | Based on connected load, confirm with layout design |
| Laboratory: hydrostatic, MFR, oxidation induction time | Medium | Required to defend service life claims in tenders |
| Fusion equipment for sample and U-bend assembly | Low | Enables value-added pre-assembled loop supply |
| Resin working capital | High | Largest ongoing cost, dominates unit economics |
| Installation, commissioning, training | Low | Included in the Faygo turnkey scope |
Two planning realities are worth stating plainly. Resin dominates the cost of a finished meter of pipe, so anything that reduces resin overuse, including tight wall control, low scrap during changeover, and accurate measurement, returns more over a machine’s life than a small saving on the purchase price. And a line that stops is far more expensive than a line that cost more, so pre-delivery testing, spare parts availability, and responsive technical support belong in the investment analysis rather than being treated as soft factors.
Energy use is the second operating lever. A grooved-feed extruder with a well-matched barrier screw converts more of its motor energy into useful melting and less into unnecessary shear heat, and inverter or servo drives on the haul-off and pumps cut idle consumption. Over a decade of continuous operation these differences accumulate into a meaningful share of the total cost of ownership.
Service, Support, and Turnkey Delivery From Faygo
Faygo supports a geothermal pipe line from first inquiry through years of production, and the commitments below are Wanplas brand-level policies applied at every Wanplas factory. The intent is straightforward: the buyer should be producing saleable pipe quickly and should never be stranded when a part fails.
Selection and engineering. Before an order is placed, Faygo engineers work from the customer’s pipe program, target output, resin grade, and utility conditions to define screw and die specification, tank lengths, haul-off and coiler sizing, and installed power. This avoids the common failure of buying a line rated for a diameter range that does not include the sizes that actually sell.
Factory consulting. Faygo provides water and electricity design, 3D factory site layout, worker configuration and training plans, and complete new factory construction support from zero. Existing producers can use the old machine replacement service for a zero-downtime upgrade, or the capacity expansion service to identify and remove bottlenecks and raise output on an existing floor.
72-hour continuous operation testing. Every line runs for 72 hours continuously in the factory before shipment, producing pipe under real conditions. Dimensions, output, stability, and control response are verified during that run. Customers are welcome to attend the test in person, which many geothermal buyers do because it is the last easy chance to adjust the configuration.
Open factory policy. Faygo, like every Wanplas factory, keeps an open factory policy and welcomes customer visits to the Zhangjiagang plant, roughly two hours from Shanghai Airport. Visitors see the machining, assembly, and test areas and can talk directly with the engineers who will build their line.
Installation, commissioning, and training. Engineers travel to site for installation and commissioning, run the line into stable production, and train operators on startup and shutdown sequences, recipe management, size changeover, die and calibration sleeve care, cooling system maintenance, and troubleshooting. Training covers not only how to run the machine but how to interpret out-of-tolerance dimensions and correct them.
Spare parts policy. Wanplas provides USD 500 free parts per year to customers, plus free replacement of damaged parts within the warranty period. Faygo also advises on the wear-part stock a pipe plant should hold locally, typically calibration sleeves, heater bands, thermocouples, seals, filter screens, and haul-off pads, so that a routine wear item never becomes a production stoppage.
Technical support and remote assistance. Online technical support is available around the clock, and remote diagnosis of control and drive issues resolves many problems without a site visit. For process questions, Faygo engineers help optimize the parameter recipe for a new resin grade or a new pipe size rather than leaving the customer to experiment.
Group-level guarantees. The Wanplas brand promises cover transportation, production capacity, and quality standards, including compensation terms if delivered quality falls short of the agreement. The brand mission, warming global customers with China plastic machinery, is expressed through these concrete commitments rather than slogans.
Turnkey scope. For buyers building a new geothermal pipe plant, Faygo delivers end-to-end: selection, design, manufacturing, installation, commissioning, training, and maintenance. A single point of responsibility across that chain is what separates a project that starts producing on schedule from one that stalls between suppliers.
Frequently Asked Questions
What diameter range should a new geothermal pipe producer start with?
Most new producers start with 16 mm to 63 mm on a coil line, because vertical U-bend legs and horizontal loop pipe fall mainly in the 25 mm to 40 mm band and ship as coils. That single configuration covers the majority of ground array demand. Header and main diameters from 63 mm to 160 mm are usually added later on a second line once district-scale contracts justify the investment.
Why is PE preferred over metal for buried ground source heat pump loops?
Polyethylene cannot corrode electrochemically, so buried loops are immune to soil chemistry, galvanic action, and stray currents that attack steel and copper. It is also joined by heat fusion, producing homogeneous joints as strong as the pipe wall, and it ships in long coils that eliminate joints inside a grouted borehole. The lower wall conductivity is outweighed by the fact that grout and ground resistance dominate the heat transfer path.
How long can a single coil be, and why does it matter for boreholes?
Coil length is limited by the coiler and by handling practicality, and geothermal producers routinely supply coils of several hundred meters. It matters because a vertical U-bend must run down the borehole and back with no joint, so a 150 meter borehole needs more than 310 meters of continuous pipe. Faygo sizes the coiler to the deepest borehole a customer expects to serve.
What causes ovality problems in coiled ground loop pipe?
Ovality usually comes from insufficient cooling before the coiler, excessive coiling tension, a coil diameter too small relative to pipe diameter, or unstable vacuum in the calibration tank. Pipe that is still warm when it is wound will take a flattened set. Adding cooling tank length, lowering the final water temperature, and controlling coiler tension normally resolves the problem.
Can one line produce both PE100 ground loop pipe and PE-RT building circuits?
Yes within limits. A 16 mm to 63 mm coil line can run PE100, PE80, and PE-RT with appropriate screw selection and recipe changes, which suits producers serving both the ground array and the building side. Very high output on one material or oxygen barrier co-extrusion is better served by a dedicated line, because the screw geometry and die configuration can then be optimized instead of compromised.
How is wall thickness controlled during production?
Wall thickness is the ratio of extruder output to haul-off speed, so the operator fixes line speed at the target and trims screw speed until measured wall sits slightly above the standard minimum. Stable melt temperature, steady melt pressure, and constant vacuum keep it there. Online ultrasonic measurement lets a producer run a smaller safety margin and save resin over the year.
What testing should a geothermal pipe plant run in house?
At minimum, dimensional checks on every shift, melt flow rate on incoming resin and finished pipe, oxidation induction time to confirm the antioxidant reserve survived processing, and hydrostatic pressure testing to the applicable standard. Notched pipe testing for slow crack growth is added when supplying tenders that demand it. These results together support a documented 50-year design life claim.
What does Faygo include with the machine after delivery?
Every line is proven with a 72-hour continuous operation test before shipment, then supported with on-site installation and commissioning, operator and maintenance training, around the clock online technical support, USD 500 free parts per year, and free replacement of damaged parts within warranty. Factory consulting for water and electricity design, 3D workshop layout, and capacity expansion is available for buyers planning a new plant.
Talk to Faygo About Your Geothermal Pipe Line
Anti-corrosion PE ground source heat pump pipe is a product where manufacturing quality is invisible at the moment of sale and decisive thirty years later. Round pipe with even walls, clean melt, preserved antioxidant reserve, and long joint-free coils is what allows a geothermal central heating pipeline engineering project to be buried and forgotten in the best possible sense. Producing that pipe consistently takes an extrusion line engineered around the diameter band, the coil length, and the resin the market actually demands.
Faygo, a Wanplas factory, brings 22 years of pipe and profile extrusion experience, three specialized factories, a 26,650 square meter FAYGOPLAST plant in Zhangjiagang, 13 national patents including 8 invention patents, and CE and ISO certified equipment covering 12 mm to 575 mm across PE, PP, and PVC. Ground loop coil lines, header lines, PE-RT and PP-R circuit lines, and corrugated conduit lines are all built on that platform, tested for 72 continuous hours before shipment, and backed by installation, training, warranty replacement, and USD 500 free parts per year.
Send your pipe program, the diameters and pressure classes you intend to sell, the deepest borehole in your market, your target annual tonnage, and your available power and water conditions, and the Faygo engineering team will return a complete line configuration with screw and die specification, tank lengths, haul-off and coiler sizing, installed power, and a workshop layout. You are equally welcome to visit the Zhangjiagang workshop, watch a geothermal pipe line running under test, and talk through factory planning, training, and capacity expansion with the engineers who will build your equipment.
