Due to its unique material properties and manufacturing process, HDPE (high-density polyethylene) pipe has become the preferred material in the field of environmental protection. The main reasons include the following aspects:
High chemical stability: HDPE is non-toxic, odorless, does not contain heavy metals or harmful additives, will not pollute water quality, and meets drinking water and food grade standards (such as FDA, NSF certification).
100% recyclable: HDPE can be melted and recycled many times, and can still maintain its performance after recycling, reducing the amount of plastic waste landfill and supporting the circular economy.
Low-temperature processing: The melting temperature (about 160°C) of HDPE pipe production is much lower than that of materials such as metal or glass, and the energy consumption is lower.
Lightweight: The weight is only 1/8 of that of metal pipes, and the energy consumption for transportation and installation is greatly reduced, reducing carbon emissions.
Corrosion and aging resistance: resistant to acid, alkali, salt, and microbial erosion, no anti-corrosion coating required, life of more than 50 years, reducing replacement frequency and resource waste.
Strong impact resistance: good flexibility, resistant to ground subsidence and earthquake, reducing the risk of leakage pollution caused by rupture.
Replacing traditional materials: It can replace high-energy-consuming materials such as cement pipes and cast iron pipes, and the production of 1 ton of HDPE pipes saves about 75% of energy compared to metal pipes.
High construction efficiency: hot-melt connection does not require chemical adhesives to avoid secondary pollution, and the joints have good sealing to prevent leakage.
Non-leakage design: HDPE pipeline system has excellent sealing to avoid sewage or chemical leakage to pollute soil and groundwater.
Application of renewable raw materials: Some HDPE pipes use bio-based polyethylene (such as ethylene extracted from sugarcane ethanol), further reducing dependence on fossil resources.
Rainwater collection and recycled water utilization: widely used in sustainable drainage systems (SUDS) and water reuse projects.
Landfill anti-seepage: used as a liner to prevent leakage of harmful substances.
Marine engineering: resistant to salt spray corrosion, can be used in eco-friendly offshore facilities.
PVC pipes: may contain plasticizers (such as phthalates), and incineration will produce dioxins.
Metal pipes: easy to rust, high energy consumption in production, and mining damages the ecological environment.
HDPE pipes have environmental advantages throughout their life cycle from raw materials, production, use to recycling, and are in line with global sustainable development goals (such as SDGs). They are particularly outstanding in the fields of water conservation, energy conservation and pollution prevention and control, making them the green first choice for municipal, industrial and agricultural projects.
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HDPE (high-density polyethylene) pipes are widely used in water supply and drainage, gas transmission and other fields due to their corrosion resistance, good flexibility and long life. Electrofusion welding is one of the common connection methods for HDPE pipes, but various problems may be encountered in actual construction. This article will introduce the common problems, cause analysis and solutions in electrofusion welding in detail to help improve the construction quality.
Electrofusion connection is to heat the HDPE material through the resistance wire inside the electrofusion sleeve (or electrofusion pipe fitting), and form a high-strength sealed joint after cooling. The key steps include:
Pipe end surface treatment (scraping oxide layer, cleaning)
Centering and fixing (avoid eccentricity)
Electric heating (control time and voltage according to manufacturer parameters)
Cooling and curing (natural cooling to avoid external interference)
1. The electric fusion joint is not firm or leaking
Possible reasons:
The oxide layer on the pipe end surface is not scraped clean, resulting in poor fusion
The electric fusion time is insufficient or the voltage is unstable, and the melting temperature is not reached
External force disturbance during cooling
Electrofusion pipe fittings or pipe materials are unqualified (such as doped recycled materials)
Solution:
Strictly handle the pipe end surface:
Use a special scraper to remove the oxide layer (scraping length ≥ electric fusion sleeve insertion depth)
Wipe with alcohol or a clean cloth to ensure that there is no oil or dust
Control heating parameters:
Set the welding machine according to the voltage and time provided by the manufacturer (different pipe diameters and ambient temperatures need to be adjusted)
Use a stabilized power supply to avoid voltage fluctuations
Ensure sufficient cooling:
Cooling time ≥ specified value (usually 20-30 minutes)
It is forbidden to move the pipe or apply pressure during cooling
Select qualified materials:
Purchase HDPE pipes and electric fusion pipe fittings that meet GB/T 13663 standards
Avoid using inferior or recycled materials
2. Smoke or fire during electric fusion
Possible causes:
Resistance wire short circuit or local overheating
Electrofusion pipes damp or internal contamination
Input voltage too high
Solution:
Check the electric fusion pipes:
Before use, check whether the internal resistance wire is intact, without breakage or deformation
Before construction in a humid environment, use a hot air gun to dry the pipes
Control voltage:
Ensure that the output voltage of the welding machine is consistent with the nominal value of the pipe (usually 39.5±0.5V)
Avoid long-term overload power
Emergency treatment:
Immediately turn off the power, replace the pipes and re-weld them after cooling
3. The observation hole is not ejected or ejected unevenly
Possible causes:
Insufficient heating time, material is not fully melted
Insufficient pipe insertion depth or large deviation in centering
Ambient temperature is too low (such as winter construction)
Solution:
Adjust construction parameters:
Extend heating time in low temperature environment (refer to manufacturer's low temperature welding parameters)
Ensure that the pipe insertion depth is aligned with the electric fusion sleeve mark
Check centering:
Use a clamp to fix the pipe to avoid eccentricity (deviation ≤10% wall thickness)
The ejection height of the observation hole should be uniform (generally protruding 1-3mm)
4. The internal diameter of the joint is reduced or blocked after electric fusion
Possible causes:
Excessive accumulation of molten material inside the joint
The pipe port is not chamfered, and the molten material does not flow smoothly
Solution:
Pre-treat the pipe port:
Use a chamferer to process a 15° groove after cutting
Ensure that there are no burrs on the inner wall of the pipe
Control the amount of fusion:
Avoid overheating (operate according to standard parameters)
Electrofusion connection is a key link in the HDPE pipe system, and quality problems may cause leakage or structural failure. The failure rate can be significantly reduced by standardizing operations (cleaning, alignment, parameter control), selecting qualified materials, and strengthening construction management.
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Company address: Room 802, 8th Floor, Building 5, Jinyin Modern City, Jinshui District, Zhengzhou City, Henan Province, China
HDPE (High-Density Polyethylene) pipes are widely used in municipal engineering due to their excellent corrosion resistance, flexibility, and long service life. To ensure project quality and durability, the following key points must be strictly observed during installation:
1. Material Inspection
Check pipe appearance: uniform color, free of bubbles, cracks, dents, or other defects.
Stiffness requirement: Municipal drainage pipes should have a ring stiffness ≥ 4000 N/m² (SN4).
Pipe end flatness: Straightness tolerance should be less than 3‰.
2. Trench Excavation
Width requirement: Pipe outer diameter + 0.3 m (for above-ground connections) or + 0.5 m (for in-trench connections), with a minimum width ≥ 0.7 m.
Base treatment: Avoid disturbing the natural soil; backfill and compact with graded gravel if over-excavated.
Groundwater control: Lower the water table to 0.3–0.5 m below the trench bottom.
1. Connection Methods
Butt Fusion (DN ≥ 75 mm): Temperature 210 ± 10°C, voltage stabilized at 200–220 V.
Electrofusion (for confined spaces): Suitable for pipe wells and restricted areas.
Socket Fusion (DN ≤ 63 mm): Control heating time to avoid excessive melt flow.
2. Special Environmental Considerations
Summer installation (DN ≤ 110 mm): Use a serpentine layout to compensate for thermal expansion.
Outdoor installation: Apply shading measures to prevent UV degradation.
Low-temperature environments (below -10°C): Use special low-temperature-resistant pipes.
3. Pipe Laying
Lowering method: Use non-metallic slings (secured at 1/4 of the pipe length from the end); never use center lifting.
Foundation treatment: Use gravel bedding (50–200 mm thick); avoid concrete foundations.
1. Backfilling Requirements
Layered backfilling: Use medium-coarse sand for pipe sides, compaction ≥ 90%.
Mechanical backfilling restriction: Only allowed above 0.7 m from the pipe crown.
Symmetrical backfilling: Backfill both sides simultaneously to prevent deformation.
2. Quality Inspection Standards
Pressure test: Use water as the medium, maintain pressure for 30 minutes.
Joint inspection: Butt fusion beads should be uniform (height ≥ 2 mm).
Alignment control: Horizontal deviation ≤ 1.5 mm/m, total length ≤ 25 mm.
1. Safety Risk Prevention
Static electricity protection: Anti-static measures required in flammable environments.
Trench safety: Install supports to prevent collapse.
Large-diameter pipes (DN ≥ 400): Require special construction plans to control rebound risks.
2. Connection with Manholes
Flexible connection: Use rubber gaskets to prevent leaks.
Anti-settlement treatment: Enhance compaction within 1 m of the manhole.
Table: Key Control Indicators for HDPE Pipes in Municipal Engineering
Item | Standard Requirement | Test Method |
Ring stiffness | ≥ SN4 (4000 N/m²) | Pressure test |
Fusion temperature | 210 ± 10°C | Infrared thermometer |
Backfill compaction | ≥ 90% (pipe sides) | Sand replacement method |
Leak tightness | 0.8 MPa/30 min, no leakage | Hydrostatic test |
By strictly adhering to these technical requirements, HDPE pipeline systems can achieve optimal performance in municipal engineering. It is recommended to conduct pre-construction technical briefings and establish a complete quality traceability system (e.g., RFID tagging) for full lifecycle quality control. For special geological conditions or large-diameter pipes (e.g., DN ≥ 800 mm steel-reinforced pipes), refer to the manufacturer’s specialized construction guidelines.
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HDPE wear-resistant pipe for mining is a pipe made of high-density polyethylene (HDPE) material, designed for high-wear and high-corrosion working conditions such as mines, ore dressing plants, and tailings transportation. Compared with traditional metal pipes, HDPE wear-resistant pipes have the advantages of light weight, corrosion resistance, impact resistance, and long service life. They are widely used in the transportation of slurry, sediment, tailings and other media.
Property | Advantage |
High Wear Resistance | Made of ultra-high molecular weight polyethylene (UHMWPE) or modified HDPE material, with 3-5 times the wear resistance of steel pipes |
Strong Corrosion Resistance | Resistant to acids, alkalis, salts, slurry and other corrosive media, service life can exceed 20 years |
Good Impact Resistance | High toughness, can withstand impact from ores and gravel, not prone to cracking |
Light Weight | Density only 1/8 that of steel pipes, easy installation, reduces transportation and construction costs |
Low Friction Coefficient | Smooth inner wall reduces flow resistance and lowers energy consumption |
Non-scaling | Resists adhesion of slurry and mud, minimizing clogging risks |
Environmentally Safe | Non-toxic and odorless, complies with mining environmental requirements |
Slurry transportation: slurry pipelines for gold, copper, iron ore, etc.
Tailing discharge: tailings transportation system for ore dressing plants
Sediment transportation: river dredging and dredging projects
Chemical media: transportation of corrosive liquids (such as acidic mine water)
Coal industry: discharge of coal slime and coal washing wastewater
(1) Material selection
Ordinary HDPE pipes: suitable for general wear environments, low cost
UHMWPE (ultra-high molecular weight polyethylene) pipes: ultra-high wear resistance, suitable for high-wear slurry transportation
Steel-plastic composite wear-resistant pipes: outer layer HDPE anti-corrosion, inner layer wear-resistant alloy, suitable for high pressure and high wear conditions
(2) Pressure level
Low pressure (0.6-1.0MPa): suitable for gravity transportation or low-pressure pipelines
Medium and high pressure (1.0-2.5MPa): suitable for pumping slurry or long-distance transportation
(3) Connection method
Flange connection: suitable for high pressure and large-diameter pipelines
Hot-melt connection: suitable for seamless long-distance laying
Electrofusion connection: suitable for complex terrain or maintenance scenarios
Comparison Item | HDPE Wear-resistant Pipe | Metal Pipe (Steel Pipe, Cast Iron Pipe) |
Wear Resistance | Excellent (3-5 times that of steel pipes) | Moderate, requires rubber or ceramic lining |
Corrosion Resistance | Outstanding, no anti-corrosion treatment needed | Prone to corrosion, requires anti-corrosion coating |
Weight | Lightweight, easy to install | Heavy, high transportation and installation costs |
Service Life | Over 20 years | 5-10 years (requires frequent maintenance) |
Maintenance Cost | Low | High (requires regular replacement and anti-corrosion treatment) |
HDPE wear-resistant pipes for mining are gradually replacing traditional metal pipes and becoming the first choice in the mining industry due to their advantages of wear resistance, corrosion resistance, light weight and long life. When selecting the type, it is necessary to select the appropriate material and connection method according to the medium characteristics, pressure requirements and installation environment to ensure the long-term stable operation of the system.
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Contact us: Email:inquiry@phtopindustry.com | Whatsapp:+86 15093100892
Company address: Room 802, 8th Floor, Building 5, Jinyin Modern City, Jinshui District, Zhengzhou City, Henan Province, China
HDPE (high-density polyethylene) pipe is more suitable for low temperature environment than PVC pipe, mainly based on the following key reasons:
1. Excellent low temperature toughness
Cold resistance: HDPE can still maintain flexibility and impact resistance in the range of -60°C to 60°C, while PVC will gradually become brittle and easy to crack below 0°C.
Impact resistance: The molecular structure of HDPE is not prone to brittle fracture at low temperatures, which is suitable for cold areas or frozen liquid transportation.
2. Material property advantages
Higher crystallinity: The high crystallinity of HDPE enables it to maintain the flexibility of the molecular chain at low temperatures, while PVC is a rigid material with a larger low-temperature shrinkage rate.
No plasticizer migration: HDPE does not need to add plasticizers (PVC needs to add), avoiding the problem of material hardening caused by the precipitation of plasticizers at low temperatures.
3. Anti-frost heave performance
Elastic deformation ability: HDPE pipes can alleviate the volume expansion of internal water when it freezes through slight deformation, reducing the risk of pipe bursting; PVC is easy to be frozen and cracked due to its strong rigidity.
Low temperature flexibility: Even if frozen, HDPE pipes can usually return to their original shape after thawing, while PVC may be permanently damaged due to brittleness.
4. Chemical corrosion resistance
Resistance to stress cracking: HDPE is more resistant to chemical media (such as salt and snow melting agents) in low temperature environments, and is suitable for municipal or industrial applications in cold areas.
5. Convenient installation and maintenance
Cold bending construction: HDPE pipes can still be bent and installed at low temperatures, reducing the number of joints; PVC pipes need to be heated or specially treated when installed in cold weather.
Reliability of hot melt connection: HDPE hot melt joints have stable sealing at low temperatures, while PVC adhesive joints may have poor curing effect at low temperatures.
Water supply/drainage in cold regions: HDPE pipes are widely used in high-latitude regions such as Northern Europe and Canada.
Refrigeration fluid transportation: low-temperature medium transportation systems such as food processing and chemical industry.
Ground source heat pump pipeline: long-term stable operation in underground low-temperature environment.
Property | HDPE | PVC |
Minimum Tolerable Temperature | -60°C | -10°C to 0°C (brittle and prone to cracking) |
Low Temperature Impact Resistance | Excellent | Poor |
Frost Heave Adaptability | Can absorb through deformation | Prone to rupture |
Joint Reliability | Stable with heat fusion connection | Adhesive joints prone to failure |
Although HDPE has excellent low temperature resistance, it is still necessary to select specially formulated HDPE (such as PE-RT) or take insulation measures under extremely low temperatures (such as below -50°C) or frequent freeze-thaw cycles.
The comprehensive properties of HDPE make it the first choice for low temperature environments, while PVC is more suitable for temperate or indoor applications.
Official website: www.phtopindustry.com | www.phpipes.com
Contact us: Email:inquiry@phtopindustry.com | Whatsapp:+86 15093100892
Company address: Room 802, 8th Floor, Building 5, Jinyin Modern City, Jinshui District, Zhengzhou City, Henan Province, China