Plastic-Coated Steel Pipes For Water Supply and Drainage

Published:2025-09-25 | Last Updated: 2026-04-21    Views: 110

I. Advantages of Plastic-Coated Steel Pipes For Water Supply and Drainage

(1) Municipal Water Supply Networks

Scenario: Urban water pipes are buried underground long-term, requiring guaranteed water quality safety and stable supply.

Challenge: Conventional steel pipes are prone to rust and scaling, compromising water quality and incurring high maintenance costs.

Solution: Coated steel pipes for water supply and drainage feature smooth, corrosion-resistant inner walls that effectively prevent scaling and rust. This ensures water safety and extends pipeline network lifespan.

(2) Industrial Circulating Water Piping

Scenario: Factory circulating water pipes continuously transport cooling water or process water.

Issue: Impurities and microorganisms in water readily cause corrosion and blockages in steel pipes, reducing circulation efficiency.

Solution: Plastic-coated steel pipes feature smooth inner walls that resist impurity adhesion, minimizing corrosion and blockages. This enhances water circulation efficiency and lowers maintenance costs.

(3) Drainage and Sewage Piping

Scenario: Sewage networks and drainage pipes require resistance to acid/alkali and microbial corrosion.

Issue: Ordinary steel pipes corrode easily, resulting in short service life and frequent maintenance disruptions.

Solution: Plastic-coated steel pipes for water supply and drainage offer excellent acid/alkali resistance and corrosion protection, withstanding sewage erosion to extend pipeline lifespan and reduce maintenance frequency.

(4) Underground Burial or Humid Environments

Scenario: Underground pipelines, riverbank or coastal networks exposed to moist soil or high salinity.

Issue: Steel pipes corrode when continuously exposed to damp soil, leading to leaks or ruptures.

Solution: The robust outer coating of plastic-coated steel pipes blocks moisture and chemical corrosion, enhancing the durability and safety of buried pipelines.

(5) Special Water Quality Requirements

Scenario: Drinking water or purified water systems requiring guaranteed water purity.

Issue: Internal rust or scale buildup in steel pipes can compromise water quality and cause secondary contamination.

Solution: The smooth inner surface of plastic-coated steel pipes prevents direct metal-water contact, eliminating rust and contamination to ensure safe and reliable water quality.

II. Parameters for Plastic-Coated Steel Pipes For Water Supply and Drainage

III. Specification and Dimension Table for Plastic-Coated Steel Pipes For Water Supply and Drainage

Table Notes:

(1) Theoretical Weight: Calculated based on carbon steel material, unit kg/m. May vary slightly depending on specific material.

(2) Allowable Working Pressure PN: Common standards for municipal water supply/drainage and industrial circulating water systems. Adjustable based on actual operating conditions.

(3) Coating Type and Thickness:

FBE: Internal anti-corrosion layer, fusion-bonded epoxy powder, corrosion-resistant

PE / PU: External protective layer, enhances mechanical protection and anti-corrosion performance

Thickness may be adjusted appropriately based on pipe diameter and project requirements

(4) Length: Standard lengths are 6 meters or 12 meters, custom lengths available.

(5) Applications: Municipal water supply and drainage, sewage discharge, industrial circulating water systems, underground buried pipelines, etc.

IV. Coating Types for Plastic-Coated Steel Pipes Used in Water Supply and Drainage

Selection Principles:

(1) Medium Priority:

Clean water or domestic water → Internal FBE coating sufficient

Sewage or industrial wastewater → Liquid epoxy or FBE + PE coating

Chemically corrosive media → Dual-layer protection (FBE + PE/PU)

(2) Construction Environment:

Underground burial → External PE or PU protective layer recommended

Indoor piping networks → Internal FBE coating sufficient

(3) Pressure and Service Life Requirements:

Standard municipal pressure ≤2.5 MPa → FBE or FBE + PE

High pressure or long-term service → Optional thick coating or dual-layer application

(4) Pipe Diameter and Application Method:

Large diameters or complex fittings → Liquid epoxy easier to apply

Small diameter straight pipes → FBE powder spraying highly efficient

V. Recommendations for Use, Maintenance, and Lifespan Extension of Plastic-Coated Steel Pipes in Water Supply and Drainage Systems

(1) Construction Phase

Avoid Scratches and Impacts: Although the outer coating of plastic-coated steel pipes provides protection, protective sleeves, soft ropes, or pallets must still be used during transportation, loading/unloading, and hoisting to prevent scratches, impacts, or crushing.

Optimize Pipe Layout: When installing pipe elbows, flanges, and supports, ensure sufficient clearance is maintained to prevent stress concentration that could damage the coating.

Joint Treatment: If the coating is cut or damaged at socket weld or flange connections, promptly repair the area to prevent corrosion from spreading through the joint.

(2) Operational Phase

Water Quality Management: Maintain clean conveyed water media. Avoid prolonged operation with water containing high concentrations of acids, alkalis, or solid particles to reduce coating wear and corrosion risks.

Pressure Control: Do not exceed the pipeline's rated working pressure (PN value) during operation to prevent coating cracking or pipeline rupture due to overpressure.

Temperature Control: Avoid prolonged conveyance of high-temperature media (>80°C) through plastic-coated steel pipes for water supply and drainage. Use insulated pipes or high-temperature resistant pipes as alternatives.

(3) Regular Inspection and Maintenance

Visual Inspection: Conduct regular visual inspections of the pipeline to check for coating peeling, cracking, scratches, or localized corrosion.

Joint Inspection: Focus on connections such as flanges, threads, and welds. Reapply coating or replace seals promptly.

Pipeline Cleaning: Clean pipelines periodically based on water quality and sediment conditions to prevent internal impurities from wearing down the coating.

(4) Environmental and Support Maintenance

Supports and Fixings: Use corrosion-resistant supports or brackets for buried or overhead pipelines to prevent localized stress concentration or compression.

Chemical Corrosion Prevention: Avoid prolonged exposure to strong acids, alkalis, or salt solutions. If unavoidable, opt for thickened FBE/PE/PU coatings or dual-layer protection.

(5) Service Life Extension Recommendations

Prompt Coating Repair: Damaged pipeline coatings must be promptly repaired using the same coating type.

Optimal Design Selection: Select appropriate pipe diameter, wall thickness, and coating type based on conveyed medium, pressure, temperature, and construction environment.

Effective Protection and Marking: Clearly identify plastic-coated steel pipes at construction sites and during operation to prevent damage from misoperation.