3LPE Coating Line for 3.5”-56” (DN89-1420mm) Steel Pipe, Full-Range Anti-Corrosion Production Equipment

Qingdao Huashida 3LPE Coating Line for 3.5”-56” (DN89-1420mm) Steel Pipe is a professional anti-corrosion coating system designed for 3.5” - 56” (DN89mm - DN1420mm) steel pipes. This line features proven configuration: sj-65/30 ad extruder (45kw, 100kg/h), sj-120/33 pe extruder (280kw, 750kg/h), wide diameter range coverage in one line, delivering reliable coating quality for oil & gas transmission, natural gas distribution, water supply, municipal pipelines, general industrial piping.

With 280kW PE extruder and 1000kW intermediate frequency heating, this system is optimized for the Global coating contractors, pipe mills with mixed diameter product range market. Backed by over 20 years of manufacturing experience since 2003, with 58 invention patents, and 50+ successful installations worldwide, Huashida ensures stable operation, low maintenance cost, and coating quality that meets international standards.

 

1. Wide diameter coverage of 3.5” - 56” (DN89mm - DN1420mm) in a single production line, reducing equipment investment for mixed-size pipe mills

2. Spiral wrapping coating technology ensures uniform PE layer thickness and excellent adhesion for 3.5” - 56” (DN89mm - DN1420mm) pipes

3. Compact O-type or side-wrap coating head design minimizes floor space requirement

4. Quick diameter changeover via PLC recipe storage, reducing setup time between production batches

5. 38CrMoAlA nitrided screw with >HV740 hardness delivers 30% higher output at same power consumption

The anti-corrosion coating processing line includes:

Coating Process: 3LPE (3-Layer Polyethylene) spiral wrapping coating

Standard 3PE Process Sequence:

Pipe Loading -> External Shot Blasting (Sa 2.5) -> Pipe Internal Air Purging
-> Pipe End Masking -> Intermediate Frequency Heating (~200deg C)
-> FBE Epoxy Powder Spraying -> AD Adhesive Extrusion & Wrapping
-> PE Extrusion & Wrapping -> Water Spray Cooling -> Joint Cutting
-> PE End Beveling -> Holiday Detection -> Finished Pipe Unloading

Coating Process: 3PE spiral wrapping coating (FBE + AD adhesive + PE), side-wrap extruder

Standard 3PE Process Sequence:

Pipe Loading -> External Shot Blasting (Sa 2.5) -> Pipe Internal Air Purging
-> Pipe End Masking -> Intermediate Frequency Heating (~200deg C)
-> FBE Epoxy Powder Spraying -> AD Adhesive Extrusion & Wrapping
-> PE Extrusion & Wrapping -> Water Spray Cooling -> Joint Cutting
-> PE End Beveling -> Holiday Detection -> Finished Pipe Unloading

3. Key Configuration

At the heart of this 3.5” - 56” (DN89mm - DN1420mm) coating line are two precision extruders: SJ-65/30 single screw extruder, 45kW, max output 100 kg/h for the adhesive layer and SJ-120/33 single screw extruder, 280kW, max output 750 kg/h for the polyethylene top layer. The screws are manufactured from 38CrMoAlA nitrided steel, with nitriding depth of 0.4-0.7mm and hardness above HV740, ensuring long service life and stable plasticization.

Supporting the extruders is 1000kW intermediate frequency heating, C-type coil, pure water cooling, heating pipes to approximately 200deg C with C-type coil and pure water cooling system. Surface preparation is handled by external shot blasting machine, 2x37kw blast wheels, 350kg/minx2, sa 2.5 grade, delivering Sa 2.5 cleaning grade with 50-90um anchor profile.

The FBE powder application station features multi-gun electrostatic spray with (n+1)x2 redundant design, recovering over 95% of powder through an integrated reclaim system. The entire line is orchestrated by internationally recognized PLC with 10-inch industrial-grade HMI touchscreen, with VFD from internationally recognized brands and industrial-grade control components.

Pipe diameter range covers 3.5” - 56” (DN89mm - DN1420mm) with standard length of 6-15 meters. Post-coating cooling uses water spray quench system (<=20deg C, >=0.3MPa, 26-30 m3/h), followed by rotary peeler knife end beveling (~40 sec/pipe with kraft paper masking). Quality verification includes high-voltage holiday detection and coating thickness measurement. Staffing requirement is 4-5 operators, with minimum workshop height of 9 meters for large diameter configurations.

Applications

This coating line is specifically suited for:

• Oil & gas transmission, natural gas distribution, water supply, municipal pipelines, general industrial piping

• Oil & gas transmission and distribution pipelines

• Municipal water supply and sewage pipelines

• Chemical plant process piping

• Mining and slurry transport pipelines

Target Market: Global coating contractors, pipe mills with mixed diameter product range

Export Countries: Russia, UAE, Saudi Arabia, Iran, Uzbekistan, Kazakhstan, Nigeria, South Africa, India, Thailand

Standards Compliance

This equipment is designed and manufactured in compliance with:

• GB/T 23257-2017

• DIN 30670

• ISO 21809-1

• ISO 8501-1 (Sa 2.5)

All coating parameters (FBE >=150um, AD >=170um, PE 3.3-4.2mm per GB/T 23257-2017) can be configured to meet project-specific inspection and test plans (ITP). Coating thickness calculated per formula: coating weight = surface area x thickness x material density.

Why Choose Qingdao Huashida

What sets Qingdao Huashida apart is not just equipment manufacturing - it is field-proven design philosophy. Unlike manufacturers who only build machines without practical production knowledge, Huashida operates its own coating factory in China. Every design improvement is refined through real production experience, ensuring that machines are battle-tested in actual coating operations before reaching customers. This hands-on approach, combined with 58 invention patents and 38 utility model patents, results in equipment that solves real production problems rather than creating new ones.

Established in 2003 and headquartered in a 33,000 m2 industrial park in Qingdao, the company employs over 100 professionals including 4 senior engineers and 15 mechanical technicians. Core technology comes from Germany, with R&D partnerships with Beijing University of Chemical Technology and other leading institutions. For oil & gas transmission, natural gas distribution, water supply, municipal pipelines, general industrial piping, this practical heritage means equipment that starts production quickly, runs stably, and requires minimal intervention - qualities that directly translate to higher profitability for coating operators.