1. Product Overview

Enamel tubes, also known as glass-lined steel tubes, are composite tubes made by applying a layer of inorganic glass enamel onto the outer surface of carbon steel tubes through high-temperature firing. Combining the high mechanical strength of steel with the excellent corrosion resistance of glass, enamel tubes are ideal for heat exchange and anti-corrosion applications in harsh industrial environments.

2. Typical Applications

Enamel tubes are widely used in:

• Coking Industry: As gas cooling tubes in primary coolers and waste heat boilers; resist tar and sulfur corrosion.

• Chemical Industry: For heat exchange and transport of acidic or alkaline gas streams.

• Metallurgy & Power Plants: For cooling high-temperature flue gas and recovering waste heat.

• Waste Incineration, Desulfurization & Denitrification Systems: Resistant to chloride ion corrosion, significantly extending service life.

3. Structural Characteristics

An enamel tube consists of two layers:

• Carbon Steel Base: Provides mechanical strength and pressure resistance.

• Glass Enamel Coating: Fired at over 800°C and tightly bonded to the steel surface to form a dense protective layer.

Common structures include:

• Smooth enamel tubes

• Internal ribbed enamel tubes (for enhanced heat transfer)

• U-tube bundles for heat exchangers

4. Key Advantages

1. Excellent Corrosion Resistance: Strong resistance to acidic gases (e.g., H₂S, SO₂, NOₓ), organic solvents, acid mist, and more.

2. Anti-Fouling, Anti-Tar Adhesion: Smooth glass surface prevents adhesion of tar and dust.

3. High Temperature Resistance: Operating temperature up to 300°C or higher.

4. Superior Insulation & Stability: Non-conductive and chemically stable.

5. Long Service Life: 2–3 times longer than carbon steel or stainless steel tubes under similar conditions.

6. Eco-Friendly: Inert, recyclable, and free of toxic emissions.

5. Quality Control & Technical Standards

Strict quality controls include:

• Uniform Coating Thickness: Typically 0.3 mm to 0.6 mm.

• Strong Adhesion: Ensures enamel firmly bonds to the steel substrate.

• Thermal Shock Resistance: Withstands rapid heating/cooling cycles.

• Spark Testing: To detect pores, bubbles, or weak spots.

• Smooth Appearance: Glossy, even coating free from cracks or drips.

6. Comparison: Enamel Tube vs Stainless Steel vs Carbon Steel

• For tar-laden or sulfur-rich high-temperature gas, ribbed enamel tubes are recommended for better heat transfer.

• For highly acidic or chloride-heavy gas, high-silica enamel or dual-layer coating is advisable.

• Avoid impact or metal friction during installation to protect the enamel layer.