MINING DOUBLE RESISTANCE PLASTIC COATED STEEL PIPE

Mining-Grade Dual-Protection Plastic-Coated Steel Pipe

(Dual-Resistance Coated Steel Pipe for Coal Mine / Underground Mining)

Mining dual-protection plastic-coated steel pipe is a steel-plastic composite pipe specially engineered for underground coal mine environments. Using a high-strength carbon steel base pipe (seamless, ERW or spiral welded) with internally and externally coated mining-grade epoxy (EP) or polyethylene (PE) powder, it delivers two mandatory safety properties:

It combines steel pipe pressure strength with plastic corrosion resistance, ideal for gas drainage, ventilation, water supply/drainage, shotcreting and mine fire-fighting systems.

2. Specification & Dimensions

EP (Epoxy spray): 100 – 400 μm

PE (Polyethylene dip-coating): 400 – 1000 μm

3PE combo: 2.5 – 4.5 mm on request

3. Base Material & Steel Grades

4. Coating & Dual-Protection Performance

Average afterflame time ≤ 3s

Single sample afterflame ≤ 10s

Self-extinguishing, no dripping

5. Executive Standards

6. End Preparation & Connections

End caps with anti-static warning tape

7. Surface Treatment & Coating System

8. Testing & Inspection

Dimensional check (OD, WT, length, ovality)

Base pipe hydrostatic test

Coating thickness measurement

Cross-cut / pull-off adhesion test

Spark (holiday) inspection

Anti-static surface resistance test

Flame-retardant burn test (MT 181)

MTC + MA certificate copy supplied

9. Typical Applications

Coal mine underground gas drainage / methane extraction

Positive & negative pressure ventilation ducts

Mine water supply, drainage, dewatering

Underground fire-fighting & sprinkler networks

Corrosive slurry / high-sulfur water transport

10. Packing & Delivery

Bundle with steel strips + end protectors

Coating contact surfaces wrapped with non-abrasive film

Marking: DN, WT, coating type, MA mark, heat no., flow direction arrow

Container or bulk shipment; 6m standard for underground handling