HDPE pipe and fitting,PVC pipe and fitting

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:

Pre-Construction Preparation

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.

 

Key Installation Techniques

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.

 

Backfilling & Quality Inspection

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.

 

Special Considerations

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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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

 

What is HDPE wear-resistant pipe for mining?

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.

 

Main characteristics of HDPE wear-resistant pipe for mining

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

 

Main application areas

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

 

Key points for selecting HDPE wear-resistant pipes for mining

(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

 

HDPE wear-resistant pipe for mining vs traditional metal pipe

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
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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.

 

Application scenarios

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.

 

Comparison summary (HDPE vs PVC in 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

 

Notes

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

 

Definition of Ring Stiffness

Ring stiffness is a core indicator for measuring the ability of a pipeline to resist deformation under external pressure (such as soil pressure, traffic load), with the unit of kN/m², indicating the deformation resistance of the pipeline under vertical load.

Formula:

Ring stiffness (SN) = EID3Ring stiffness (SN) = D3EI?

EE: Material elastic modulus

II: Pipe section moment of inertia

DD: Pipe diameter

 

HDPE pipe ring stiffness grade standard

International general standards (such as ISO 9969, ASTM D2412) classify ring stiffness into the following grades:

Grade	Ring Stiffness (kN/m²)	Application Scenarios
SN2	≥2	Low-load areas (e.g., green space drainage)
SN4	≥4	Light-duty roads, residential drainage
SN8	≥8	Municipal roads, general traffic areas
SN12.5	≥12.5	Heavy vehicle traffic (e.g., highways)
SN16	≥16	Ultra-deep burial or extreme load conditions

 

Key factors affecting ring stiffness

Pipe structure:

Solid wall pipe: high stiffness, suitable for high-pressure scenarios (such as SN8 and above).

Double-wall corrugated pipe: hollow structure is lightweight, but can reach SN4-SN8 through corrugated design.

Steel belt reinforced pipe: composite steel belt support, can reach SN12.5-SN16.

Material density: The density of HDPE raw material (usually ≥0.941g/cm³) directly affects rigidity.

Wall thickness design: Under the same diameter, increasing wall thickness can significantly improve ring stiffness.

 

How to choose the appropriate ring stiffness level?

Buried depth <1m: SN4 (such as courtyard drainage).

Buried depth 1-3m: SN8 (municipal road).

Buried depth >3m or heavy load: SN12.5-SN16 (need to be calculated in combination with soil quality).

Dynamic load: areas with frequent traffic need to increase by 1-2 levels (such as SN8→SN12.5).

 

Test methods and certification

Laboratory test: Perform three-point loading test according to ISO 9969 to measure the deformation rate of pipes.

On-site verification: Deformation rate detection is required after construction (usually required to be ≤5%).

Certification standards:

National standard: GB/T 19472.1 (buried polyethylene double-wall corrugated pipe)

European standard: EN 13476 (structural wall pipe system)

 

Common misunderstandings and precautions

Misunderstanding 1: The higher the ring stiffness, the better?

→ Excessive pursuit of high stiffness may increase costs, and it is necessary to balance load requirements and economy.

Misunderstanding 2: HDPE pipe flexibility = low stiffness?

→ Structural design (such as corrugation, reinforcement layer) can take into account flexibility and high stiffness.

Construction points:

Backfill materials should use coarse sand or gravel to avoid sharp stones damaging the pipe wall.

Layer compaction to prevent local stress concentration.

 

Comparison with other materials

Pipe Type	Typical Ring Stiffness (kN/m²)	Characteristics
HDPE Double-Wall Corrugated Pipe	SN4–SN8	Lightweight, economical, suitable for general drainage
HDPE Steel Belt Reinforced Pipe	SN8–SN16	Ultra-high strength, ideal for deep burial or heavy load conditions
PVC Solid Wall Pipe	SN2–SN4	High rigidity but poor impact resistance
Concrete Pipe	≥20	Heavy and costly to install

 

The ring stiffness level of HDPE pipe directly determines its engineering applicability. When selecting, it is necessary to comprehensively evaluate the burial depth, load, soil quality and cost. For high-demand scenarios (such as municipal trunk roads), it is recommended to choose SN8 or above and match it with a steel belt reinforcement structure to ensure long-term stability.

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

 

 

PE100 grade HDPE pipe refers to pipes made of PE100 grade in high-density polyethylene (HDPE) material.

What is PE100?

PE (Polyethylene) Grading: HDPE materials are divided into different grades according to density, mechanical properties and pressure resistance, and the common ones are PE32, PE63, PE80 and PE100.

PE100 is the highest performance grade at present, with higher compressive strength, crack propagation resistance and long-term durability.

The number (such as 100) represents the minimum required strength (MRS) in MPa. The MRS of PE100 is 10 MPa, which is an upgraded version of PE80 (8 MPa).

 

Characteristics of PE100 grade HDPE pipe

High strength: can withstand higher pressure (common pressure grades: PN10, PN16, etc.), suitable for high-pressure scenarios such as water and gas transmission.

Chemical corrosion resistance: Resistant to acids, alkalis, salts and other chemicals, suitable for industrial wastewater systems.

Lightweight and flexible: Lightweight (only 1/8 of metal pipes), easy to transport and install, and can be bent to adapt to the terrain.

Long life: Design life can reach more than 50 years, UV resistance (if carbon black is added) and environmental stress cracking resistance.

Environmentally friendly and non-toxic: Meets drinking water standards (such as ISO 4427) and is often used in water supply networks.

 

Common application areas

Water supply system: municipal tap water, direct drinking water pipeline.

Gas transmission: medium and low pressure gas pipeline network (must comply with standards such as ISO 4437).

Industrial pipeline: chemical fluid, slurry transportation.

Drainage/sewage system: strong corrosion resistance, suitable for rainwater and sewage discharge.

 

Comparison between PE100 and PE80

Feature	PE100	PE80
Minimum Required Strength (MRS)	10 MPa	8 MPa
Pressure Capacity	Higher (achieves same pressure with thinner wall)	Lower
Crack Resistance	Superior	Moderate
Cost	Slightly higher	Lower

 

International Standard Reference

ISO 4427: Production and testing standard for PE100 water supply pipes.

EN 12201: European standard for HDPE pipes for water supply.

GB/T 13663: National standard for PE pipes for water supply in China.

PE100 grade HDPE pipes have become the preferred material for modern pipeline engineering due to their high strength, corrosion resistance and long life, especially suitable for high-pressure and high-demand application scenarios. When choosing, pay attention to the certification standards (such as ISO or GB) and the actual working conditions.

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