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About us
Tianjin lefin Industrial
TIANJIN LEFIN STEEL GROUP containing Tianjin lefin Industrial Co.,Ltd. 、Tianjin lefin steel import & export Co.,Ltd and Tianjin Shengqifeng International Trading Co., Ltd. -
Products
Steel Pipe Processing
Our main products include 1/2inch to 16 inch ERW PIPE/GI PIPE which has been produced according to BS1387/ASTM A53/EN10219/EN10255/EN10217 Standard -
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Service Capability
Guarantee Quality
Our steel pipes are suitable for oil, natural gas, shipbuilding, chemical industry, water conservancy, electrical, steel structure, construction and other related fields.
- Details
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Basic definition and structure
• Base material:Electric Resistance Welded Pipe (ERW), a steel pipe that is welded by rolling steel strips through the high-frequency resistance welding process. The material is usually carbon steel (such as Q235, ASTM A53) or low alloy steel.
• Coating:The surface is coated with black Varnish or anti-rust paint to form a uniform and dense protective layer to prevent corrosion and enhance aesthetics.
• Typical use:Suitable for scenes requiring rust prevention, mild corrosion prevention and appearance, such as building structure, interior decoration, low pressure fluid transportation, etc.
Production process flow
1. ERW steel pipe manufacturing:
• Strip pretreatment → coil forming → high frequency resistance welding → weld grinding → sizing and straightening → Cutting → non-destructive testing (such as ultrasonic or eddy current testing).2. Coating process:
• Surface treatment: sandblasting or pickling to remove oxide and impurities on the surface of the steel pipe and enhance the adhesion of the coating.
• Primer coating: Spray epoxy primer or zinc-rich primer (optional) to provide basic rust protection.
• Top coat: Spray black varnish or polyester/polyurethane top coat to create an even black coat.
• Curing: Hardening of the coating by baking or natural drying.Our products
Standard: (Europe) BS EN 10210, BS EN 10219
(American) ASTM A500, ASTM A501
(China) GB/T 3094, GB/T 6728, GB/T 3091
(Japan) JIS G3466
(Australia) AS 1163Outside diameter: (CHS)20-660mm Wall Thickness: 1.3mm-16mm
Outside diameter: (SHS)20*20-1200*1200mm Wall Thickness: 1.3mm-50mm
Outside diameter: (RHS)20*30-1200*1500mm Wall Thickness:1.2-50mm
Length:4m, 6m, 12m or as your required
Coating characteristics and advantages
Rust and corrosion prevention:isolated from water, oxygen and corrosive media, suitable for ordinary atmospheric environment or mild humid conditions.
Decorative:Black matte or glossy surfaces to meet the aesthetic needs of architecture, furniture and other scenes.
Environmentally friendly:Water-based varnishes or low VOC paints comply with environmental standards (e.g. RoHS).
Economy:The cost is lower than hot dip galvanizing, spraying and other processes, suitable for projects with limited budgets.
Technical parameters and standards
Steel pipe specifications:
• Outer diameter: 1/2 inch to 24 inches (DN15 to DN600)
• Wall thickness: 1.0mm~20mm (SCH40, SCH80, etc.)
• Length: Usually 6 meters or 12 meters, can be customized.Coating properties:
• Coating thickness: 20~50 microns (single layer), double layer coating up to 80 microns.
• Adhesion: Grade 1 (no shedding) in the grid test (ISO 2409).
• Salt spray resistance: 500~1000 hours (ASTM B117).Implementation standards:
• Steel pipe: ASTM A53/A135 (structural), API 5L (pipeline).
• Coating: ISO 12944 (Corrosion resistant coatings), ASTM D7091 (coating thickness test).Typical application field
1. Architecture and Decoration:
• Indoor and outdoor railings, stair railings, curtain wall supports (black matte finish to enhance the modern feel).
• Furniture frame, display rack, etc. (both rust-proof and beautiful).2. Low pressure fluid transport:
• Domestic water and air conditioning refrigerant pipes (ensure that the coating is non-toxic and meets hygiene standards).
• Ventilation pipes and cable bushings (black coating conceals well).3. Mechanical equipment:
• Conveyor frame, agricultural machinery parts (rust resistant and easy to clean).
Comparison with other coatings
Coating Type & Advantages & Limitations
Black Paint Coating：Advantages in low cost, color control.But its corrosion resistance is weaker than galvanized/spray.
Hot Dip Galvanizing :It has strong corrosion resistance (more than 50 years of life). But normally high cost, silver gray surface and need two times painting.
Spray (epoxy):It has high wear resistance, chemical corrosion resistance.But its equipment investment is suitable for mass production.
Selection suggestions
• Normal environment (e.g. indoor drying) :single layer black varnish coating (economical and practical).
• Humid environments (such as basements) :double coat primer + top coat (enhanced protection).
• Outdoor long-term use:It is recommended to choose hot dip galvanizing + black spray (double protection).
BLACK VARNISH COATING ERW PIPE
Subcategory
Keyword
- Details
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Basic definition and structure
• Base material:Electric Resistance Welded Pipe (ERW), a steel pipe that is welded by rolling steel strips through the high-frequency resistance welding process. The material is usually carbon steel (such as Q235, ASTM A53) or low alloy steel.
• Coating:The surface is coated with black Varnish or anti-rust paint to form a uniform and dense protective layer to prevent corrosion and enhance aesthetics.
• Typical use:Suitable for scenes requiring rust prevention, mild corrosion prevention and appearance, such as building structure, interior decoration, low pressure fluid transportation, etc.
Production process flow
1. ERW steel pipe manufacturing:
• Strip pretreatment → coil forming → high frequency resistance welding → weld grinding → sizing and straightening → Cutting → non-destructive testing (such as ultrasonic or eddy current testing).2. Coating process:
• Surface treatment: sandblasting or pickling to remove oxide and impurities on the surface of the steel pipe and enhance the adhesion of the coating.
• Primer coating: Spray epoxy primer or zinc-rich primer (optional) to provide basic rust protection.
• Top coat: Spray black varnish or polyester/polyurethane top coat to create an even black coat.
• Curing: Hardening of the coating by baking or natural drying.Our products
Standard: (Europe) BS EN 10210, BS EN 10219
(American) ASTM A500, ASTM A501
(China) GB/T 3094, GB/T 6728, GB/T 3091
(Japan) JIS G3466
(Australia) AS 1163Outside diameter: (CHS)20-660mm Wall Thickness: 1.3mm-16mm
Outside diameter: (SHS)20*20-1200*1200mm Wall Thickness: 1.3mm-50mm
Outside diameter: (RHS)20*30-1200*1500mm Wall Thickness:1.2-50mm
Length:4m, 6m, 12m or as your required
Coating characteristics and advantages
Rust and corrosion prevention:isolated from water, oxygen and corrosive media, suitable for ordinary atmospheric environment or mild humid conditions.
Decorative:Black matte or glossy surfaces to meet the aesthetic needs of architecture, furniture and other scenes.
Environmentally friendly:Water-based varnishes or low VOC paints comply with environmental standards (e.g. RoHS).
Economy:The cost is lower than hot dip galvanizing, spraying and other processes, suitable for projects with limited budgets.
Technical parameters and standards
Steel pipe specifications:
• Outer diameter: 1/2 inch to 24 inches (DN15 to DN600)
• Wall thickness: 1.0mm~20mm (SCH40, SCH80, etc.)
• Length: Usually 6 meters or 12 meters, can be customized.Coating properties:
• Coating thickness: 20~50 microns (single layer), double layer coating up to 80 microns.
• Adhesion: Grade 1 (no shedding) in the grid test (ISO 2409).
• Salt spray resistance: 500~1000 hours (ASTM B117).Implementation standards:
• Steel pipe: ASTM A53/A135 (structural), API 5L (pipeline).
• Coating: ISO 12944 (Corrosion resistant coatings), ASTM D7091 (coating thickness test).Typical application field
1. Architecture and Decoration:
• Indoor and outdoor railings, stair railings, curtain wall supports (black matte finish to enhance the modern feel).
• Furniture frame, display rack, etc. (both rust-proof and beautiful).2. Low pressure fluid transport:
• Domestic water and air conditioning refrigerant pipes (ensure that the coating is non-toxic and meets hygiene standards).
• Ventilation pipes and cable bushings (black coating conceals well).3. Mechanical equipment:
• Conveyor frame, agricultural machinery parts (rust resistant and easy to clean).Comparison with other coatings
Coating Type & Advantages & Limitations
Black Paint Coating：Advantages in low cost, color control.But its corrosion resistance is weaker than galvanized/spray.
Hot Dip Galvanizing :It has strong corrosion resistance (more than 50 years of life). But normally high cost, silver gray surface and need two times painting.
Spray (epoxy):It has high wear resistance, chemical corrosion resistance.But its equipment investment is suitable for mass production.
Selection suggestions
• Normal environment (e.g. indoor drying) :single layer black varnish coating (economical and practical).
• Humid environments (such as basements) :double coat primer + top coat (enhanced protection).
• Outdoor long-term use:It is recommended to choose hot dip galvanizing + black spray (double protection).
Related products
Product Consulting
Address: Hengtai Road,Daqiuzhuang Town,Jinghai County,Tianjin,China
Mob: +8615122229899(whatspp)
Phone: +86 22 58171905
Fax: +86 22 58171902
E-mail:info@lefinsteel.com
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