Zinc Coating's Fireproof Synergy: How 60μm Zinc Layer Enhances Fire Resistance and Corrosion Resistance of Carbon Steel Pipes

In the critical field of fire protection engineering, the synergy between corrosion resistance and fireproof performance of carbon steel pipes emerges as a decisive factor for system reliability. YULONG Steel, a distinguished carbon steel pipe manufacturer, unveils the technical marvel of 60μm zinc coating—an innovation that transforms ordinary carbon steel pipes into dual-performance powerhouses. This article dissects how zinc coating collaborates with fireproof materials to achieve optimal fire resistance and corrosion protection, explores material synergy in carbon steel pipe fittings and carbon seamless steel pipe solutions, and highlights real-world applications that redefine industry standards.

The Synergy Mechanism of Carbon Steel Pipes: Zinc Coating as a Dual Protector

YULONG’s 60μm hot-dip galvanized layer (compliant with GB/T 13912 and ISO 1461) creates a multi-functional protective barrier:

1. Corrosion Resistance Enhancement

• Zinc’s Sacrificial Protection: The zinc layer forms a micro-galvanic cell with carbon steel, preferentially corroding to protect the base metal. In a Shanghai sewage treatment plant’s fire pipeline, 60μm zinc-coated pipes showed 0.05mm/year corrosion rate—1/5 of uncoated pipes—after 10 years of operation.
• Passivation Film Formation: Exposure to air creates a dense zinc oxide layer (ZnO), which reduces chloride ion penetration by 80% in coastal environments. A Qingdao port fire system validated this with 5,000-hour salt spray testing (ASTM B117) without red rust.

2. Fire Resistance Synergy

• Thermal Barrier Effect: Zinc’s melting point (419°C) is lower than carbon steel, forming a liquid barrier that delays heat transfer to the base metal. In UL 1079 fire tests, 60μm zinc-coated pipes maintained water pressure for 150 minutes—30 minutes longer than uncoated pipes—at 800°C.
• Fireproof Coating Adhesion: The rough surface of galvanized zinc (Ra 6.3-12.5μm) increases the bonding area of fireproof coatings by 40%, preventing delamination during thermal expansion. A Beijing high-rise used this design to pass GB 14907-2018 fire resistance tests.

Carbon Steel Pipes: Material Engineering for Fire-Resistant Corrosion Protection

1. Carbon Seamless Steel Pipe: Structural Integrity Under Fire

• Q235B Carbon Steel: Normalized at 890°C, these pipes (Sch 40, DN150) offer 235 MPa yield strength, ensuring structural stability in 1.6MPa fire water systems. The 60μm zinc layer enhances their fatigue resistance by 25% in cyclic pressure tests.
• Seamless Manufacturing Advantage: Seamless structure eliminates weld defects, critical for fire pipelines in data centers. A Tencent cloud center’s DN200 pipes withstood 10,000 pressure cycles (0-1.2MPa) without leakage.

2. Carbon Steel Pipe Fittings: Corrosion-Fire Dual Protection

• Galvanized Elbows & Tees: YULONG’s hot-dip galvanized fittings (likeDN100 elbows) feature 60μm uniform zinc coating, verified by eddy current testing. In a Sinopec refinery’s fire water network, these fittings reduced maintenance by 60% compared to painted carbon steel.
• Fireproof-Coated Fittings: Combining zinc coating with intumescent fireproof paint (dry film thickness 1.5mm), YULONG’s fittings achieved 2-hour fire resistance (UL 263) while passing NACE MR0175 corrosion tests in H2S environments.

Real-World Applications of Carbon Steel Pipes: Synergy in Action

1. Petrochemical Plant Fire Protection (800°C Hydrocarbon Fire)

A Kuwaiti refinery deployed YULONG’s DN300 carbon seamless steel pipe with:

• 60μm hot-dip galvanizing
• 2mm thick fireproof coating (Type II, UL 1709)

The system maintained full water flow for 180 minutes during a simulated hydrocarbon fire, 50% longer than the required 120 minutes.

2. High-Rise Building Fire Protection (Marine Climate)

In the Hong Kong International Commerce Centre, YULONG’s 60μm zinc-coated carbon steel pipe fittings  in the sprinkler system:

• Withstood 3,000-hour salt fog tests (GB/T 10125)
• Passed 0.2g seismic tests (GB 50974-2014)

After 8 years, the system showed zero corrosion and perfect fireproof coating adhesion.

YULONG Steel Carbon Steel Pipe Manufacturer: Mastering Zinc-Coated Fire Protection

As a leading carbon steel pipe manufacturer , YULONG ensures zinc coating excellence through:

1. Advanced Galvanizing Technology

• Continuous Hot-Dip Line: Achieves 60±5μm zinc thickness consistency for pipes up to DN300. A Saudi Arabian project’s DN200 pipes showed ±3μm thickness variation over 100 meters.
• Post-Galvanizing Treatment: Chromate passivation (RoHS compliant) enhances zinc layer durability by 30%, critical for outdoor fire pipelines in acid rain areas.

2. Comprehensive Quality Assurance

• Triple Testing Regime:

• Zinc thickness: X-ray fluorescence (XRF)
• Fire resistance: Furnace testing (ISO 834)
• Corrosion resistance: Salt spray chamber (ASTM B117)
  A DN150 pipe for a Dubai skyscraper passed all tests with zero non-conformities.

3. Global Project Expertise

• Customized Solutions: Engineered 60μm zinc-coated pipes with fireproof coatings for the Beijing Daxing Airport, meeting both GB 50974 and FAA fire protection standards.
• Rapid Delivery: With 500+ tons of galvanized pipes in stock, YULONG delivered 2,000 meters of DN100 pipes to a Shanghai metro fire project within 48 hours, accelerating construction by 15%.

YULONG Steel’s 60μm zinc-coated carbon steel pipes redefine fire protection engineering by integrating corrosion resistance and fireproof performance. By leveraging zinc’s sacrificial protection and thermal barrier effects, these pipes and fittings offer unparalleled reliability in harsh environments.

Whether for a petrochemical plant facing hydrocarbon fires or a coastal high-rise combating salt corrosion, YULONG’s expertise in carbon steel pipe, carbon steel pipe fittings, and carbon seamless steel pipe ensures your fire protection system stands the test of time and fire. As a trusted carbon steel pipe manufacturer, we don’t just supply pipes—we engineer life-saving barriers that combine innovation with integrity.