As a key component of modern industrial pipeline systems, high-density polyethylene (HDPE) pipes have been widely used in many industrial fields due to their excellent physical and chemical properties and economic benefits. With the advancement of materials science and manufacturing technology, HDPE pipes are gradually replacing traditional metal pipes and becoming the preferred solution for industrial fluid delivery systems. This article will systematically explore the technical characteristics and main application areas of HDPE pipe for industrial applications.
1. Material properties
HDPE (high-density polyethylene) is a thermoplastic material made from ethylene polymerization, with a linear molecular structure and high crystallinity. Its unique molecular structure gives it a series of excellent properties:
Density range: 0.941-0.965 g/cm³
Melt index: 0.1-20 g/10min (adjusted according to application requirements)
Crystallinity: 60%-80%
2. Physical and mechanical properties
High strength: tensile strength can reach 20-32MPa
High toughness: elongation at break exceeds 600%
Impact resistance: good impact resistance even in low temperature environment
Flexibility: bending radius can reach 20-25 times the pipe diameter
3. Chemical stability
Acid and alkali resistance: can resist most inorganic acids, alkalis and salt solutions
Solvent resistance: good tolerance to alcohols, vegetable oils, etc.
Environmental stress cracking resistance: excellent ESCR performance
4. Other characteristics
Operating temperature range: -40℃ to 60℃ (up to 80℃ for short term)
Thermal conductivity: 0.42-0.51 W/(m·K)
Thermal expansion coefficient: 1.5×10⁻⁴/℃
1. Chemical industry
Corrosive media transportation: pipeline transportation system for chemical raw materials such as acid, alkali, and salt solution
Process pipeline: reactor connecting pipeline, distillation system pipeline
Exhaust gas treatment system: ideal choice for corrosion-resistant exhaust pipeline
2. Petroleum and natural gas
Oil field gathering pipeline: used for the collection and transportation of crude oil and produced water
Gas transportation: medium and low pressure urban gas distribution system
Gas station pipeline: connecting pipeline between underground oil storage tank and gas dispenser
3. Electric power industry
Cable protection casing: protection system for underground laying of high-voltage cables
Power plant circulating water system: cooling water, desalted water transportation pipeline
Desulfurization system: slurry transportation pipeline in flue gas desulfurization device
4. Food and pharmaceutical
Food-grade pipeline: raw material transportation system that meets FDA standards
Pharmaceutical process pipeline: high-purity water, liquid medicine transportation system
CIP system: ideal pipeline material for in-situ cleaning system
5. Water treatment industry
Water supply and drainage system: municipal and industrial water supply and drainage network
Sewage treatment: corrosion-resistant sewage collection and transportation pipeline
Seawater desalination: pretreatment system pipeline resistant to seawater corrosion
6. Mining and Metallurgy
Slurry Transportation: Long-distance transportation of various types of ore slurries
Tailings Treatment: Mine tailings discharge and backfill system
Metallurgical Wastewater: Collection and treatment system of heavy metal wastewater
1. Comparative advantages with traditional metal pipelines
|
Performance Indicator |
HDPE Pipes |
Metal Pipes |
|
Corrosion Resistance |
Excellent |
Requires anti-corrosion treatment |
|
Weight |
Light (Density 0.95g/cm³) |
Heavy (Steel 7.85g/cm³) |
|
Installation Efficiency |
High (Quick heat-fusion joining) |
Low (Complex welding/flange connections) |
|
Flow Characteristics |
Smooth inner wall (C=150) |
Rough (C=100-120) |
|
Maintenance Cost |
Very low |
High (Requires regular anti-corrosion maintenance) |
|
Service Life |
Over 50 years |
15-30 years |
2. Outstanding engineering performance
Excellent hydraulic characteristics: smooth inner wall, low friction coefficient, and 30% higher conveying capacity than metal pipes of the same specification
Good fatigue resistance: can withstand pressure fluctuations, suitable for pulse conveying systems
Leak-free connection: hot-melt connection forms an overall system to prevent interface leakage
Strong seismic resistance: flexible structure can adapt to a certain degree of foundation settlement and seismic displacement
3. Environmentally friendly characteristics
Non-toxic and harmless: meets drinking water and food grade standards
Recyclable: 100% recyclable materials, green and environmentally friendly
Low carbon emissions: production energy consumption is only 1/3 of that of steel pipes
Pollution-free installation: no anti-corrosion coating is required, and the construction process is pollution-free
1. Determination of design parameters
Working pressure: select pressure level according to PN or SDR series
Medium temperature: consider the impact of temperature on long-term hydrostatic strength
Environmental conditions: external factors such as ultraviolet exposure and soil corrosiveness
Flow requirements: consider economic flow rate (1-3m/s) when calculating pipe diameter
2. Material selection
PE80: general pressure pipeline application
PE100: high pressure pipeline system, with higher long-term strength
PE100-RC: anti-rapid crack extension type, used in critical applications
Special modification: adding special requirements such as UV resistance and conductive layer
3. Structural design considerations
Wall thickness calculation: determine the minimum required wall thickness according to ISO 12162 standard
Support spacing: consider that the pipeline deflection does not exceed the allowable value
Expansion compensation: expansion rings or compensators are required for long straight pipe sections
Protection measures: add casing or protective layer when necessary
1. Connection technology
Hot-melt butt joint: suitable for large-diameter pipes (DN ≥ 90mm)
Electric fusion connection: suitable for small-diameter or space-constrained occasions
Mechanical connection: flange type, clamp type and other detachable connection methods
2. Laying method
Underground burial: minimum cover thickness should meet the requirements of the specification
Ground laying: need to consider fixed brackets and temperature compensation
Overhead installation: use special pipe racks and UV protection measures
Underwater laying: need counterweight design and anti-floating measures
3. Quality control points
Material acceptance: check the raw material brand, production date and quality inspection report
Welding process: strictly control the heating temperature, time and pressure parameters
Pressure test: strength test and tightness test meet the standards
Completion measurement: including location, elevation and anti-corrosion detection, etc.
1. Comparison of cost structure
|
Cost Item |
HDPE Pipe System |
Metal Pipe System |
|
Material Cost |
Moderate |
High (higher for special alloys) |
|
Installation Cost |
Low (30-50% savings) |
High |
|
Maintenance Cost |
Very low (~10% of metal) |
High |
|
Service Life |
50+ years |
15-30 years |
|
Residual Value |
Recyclable |
Partially recyclable |
2. Cost advantage throughout the life cycle
High return on investment: Although the initial investment may be comparable, the long-term operating costs are significantly reduced
Energy-saving benefits: Low hydraulic loss, 15-30% reduction in pumping energy consumption
Low loss of production stoppage: Simple maintenance, reducing system downtime
Extended asset life: Corrosion resistance extends system service life
1. International main standards
ISO 4427: Specification for PE pipes for water supply
ISO 4437: PE pipe systems for gas transmission
ASTM D3350: Standard specification for PE plastic pipes
EN 12201: PE pipe systems for pressure water transmission
2. Domestic related standards
GB/T 13663: National standard for PE pipes for water supply
GB 15558: Buried PE pipe systems for gas
CJ/T 250: PE pipes for urban drainage
HDPE pipes have become an important part of modern industrial infrastructure with their comprehensive performance advantages and evolving technological potential. With the advancement of materials science and the accumulation of engineering experience, HDPE pipes will play a key role in a wider range of industrial fields, providing strong guarantees for the reliability, economy and sustainability of industrial processes.
