3PE coating anti-corrosive steel Pipe

Update time：2025-03-27

I. 3PE anti-corrosion technology core principle

3PE coating anti-corrosion steel pipe using a triple composite protection system, combining chemical protection, mechanical protection and adhesive enhancement of the three technical advantages. Its core structure includes:

(1) the bottom layer of FBE epoxy powder (80-150μm): through electrostatic spraying to form chemical bonding, providing the basic anti-corrosion barrier

(2) Intermediate copolymer adhesive (200-300μm): realizes interfacial fusion at the molecular level.

(3) Outer layer of high-density polyethylene (2.5-4.0mm): constitutes a physical protective shield.

This synergistic protection mechanism makes 3PE coated anti-corrosion steel pipe maintain 99.2% market share in the field of buried pipelines. According to NACE standard test, its cathodic stripping distance is only 1/3 of the traditional single-layer FBE coating.

II. Product classification and technical differences

(1) General grade 3PE anti-corrosion steel pipe

Applicable to conventional corrosive environment (soil resistivity>20Ω-m), the implementation of SY/T0413 standard, the total thickness of the coating 2.5-3.2mm, economic solutions, annual corrosion rate <0.01mm.

(2) 3PE reinforced anti-corrosion steel pipe

Adopting modified polyethylene (PE-RT) and thickening coating (3.5-4.0mm), certified by API RP 5L7, suitable for high salinity (Cl- concentration >5000mg/L) and alternating freezing and thawing areas, with stripping strength increased by 40%.

(3) 3PE anti-corrosion seamless steel pipe

Taking ASTM A106 Gr.B seamless pipe as the base material, it is especially suitable for high-pressure transportation (PN＞10MPa) and heat pipe network. Its non-welded seam characteristic enhances the stress corrosion resistance by 60%, and realizes zero leakage record in the practical application of Alaska oil pipeline.

III. Intelligent production process innovation

Modern 3PE production line integrates six intelligent modules:

(1) Substrate pretreatment system

Adopting laser cleaning + plasma activation technology, the surface cleanliness reaches Sa3 level, and the roughness is controlled 40-80μm.

(2) Three-layer co-extrusion equipment

Equipped with Siemens S7-1500 control system to realize:

Epoxy powder spraying precision ±5μm

Thickness fluctuation of adhesive layer＜3%.

PE layer ellipticity≤1.5%.

(3) Online quality monitoring

Integration:

High-frequency electric spark detection (9kV/mm)

Infrared thermal imaging coating analysis

Laser thickness measurement system (accuracy 0.01mm)

This process increases the production speed to 15m/min, the product qualification rate reaches 99.98%, and saves 30% energy compared with the traditional process.

IV.  The analysis of engineering application scenarios

(1) Oil and gas transportation field

Gas gathering and transportation: 3PE reinforced anti-corrosion steel pipe successfully resisted the extreme environment of H2S concentration of 800ppm in Sichuan.

Submarine pipeline: 3PE anticorrosive seamless steel pipe passed DNV OS-F101 certification, and its service depth exceeded 500 meters.

(2) Municipal engineering applications

Intelligent Pipe Corridor: General-grade 3PE steel pipe with RFID tags, realizing 50 years of no-excavation maintenance.

Recycled water system: NSF/ANSI 61 certified, lead precipitation <0.25μg/L.

(3) Industrial Special Scenarios

Chemical industry park: 3PE reinforced type is resistant to 98% concentrated sulfuric acid for 240 hours without penetration.

Low temperature project: 3PE anticorrosion seamless steel pipe maintains toughness in LNG project (-196℃)

V. Installation and maintenance of key technologies

(1) On-site construction specifications

Pipe trench treatment: slope ≤ 15 °, gravel bedding thickness ≥ 300mm

Welding process: CRC automatic welding machine, preheating temperature 110 ± 10 ° C

Mending technology: double-layer radiation crosslinking heat shrinkable sleeve, peeling strength ≥70N/cm

(2) Full life cycle management

Establish digital twin system for real-time monitoring:

Coating impedance (>10^8Ω-m²)

Cathodic protection potential (-0.85～-1.2V CSE)

Stress corrosion crack extension rate (＜10^-9m/s)

VI. environmental standards and sustainable development

3PE coated anti-corrosion steel pipe has passed three major certification systems:

LEED certification: production energy consumption <35kWh/tonne

EPD statement: carbon footprint 4.2kgCO2/m (55% lower than traditional pipe)

Cradle to Cradle: material recycling rate >98%

Developed bio-based polyethylene coating with 30% sugarcane ethanol feedstock and 90% lower VOC emissions, which has been successfully applied in California water projects.