Extra Large Diameter 3PE Coating Line for DN630-3620mm Steel Pipe, Ultra-Large Anti-Corrosion Production Equipment

Qingdao Huashida Extra Large Diameter 3PE Coating Line for DN630-3620mm Steel Pipe is a professional anti-corrosion coating system designed for DN630mm - DN3620mm (max DN3620mm) steel pipes. This line features industry-leading large-diameter capability, proven DN3600mm project delivery in china, custom heavy-duty conveying and heating systems, delivering reliable coating quality for super-large diameter water diversion projects, coastal power plant cooling water lines, large-scale municipal drainage and flood control.

With 400kW PE extruder and 1000kW intermediate frequency heating, this system is optimized for the China, India, Southeast Asia, large-scale water infrastructure projects 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 DN630mm - DN3620mm (max DN3620mm) 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 DN630mm - DN3620mm (max DN3620mm) pipes

3. Heavy-duty spiral conveyor with individual wheel drive handles large-diameter heavy pipes stably

4. Multi-zone intermediate frequency heating ensures uniform temperature across large pipe circumference

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

The anti-corrosion coating processing line includes:
-steel pipe transmission system
-Internal and external shot blasting system
-dust collection system
-pipe heating system
-electrostatic spraying system
-PE coating system
-water cooling system
-end cutting system
-hydraulic and pneumatic system
-testing system
-electronic control system

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

Designed for pipe diameter range of DN630mm - DN3620mm (max DN3620mm), this production line handles standard pipe lengths of 6-15 meters (12m standard). The line begins with external shot blasting using external shot blasting machine, 2x37kw blast wheels, 350kg/minx2, sa 2.5 grade, achieving Sa 2.5 cleaning grade per ISO 8501-1 with anchor profile depth of 50-90um.

Following surface preparation, the 1000kw intermediate frequency heating, c-type coil, pure water cooling brings the pipe to approximately 200deg C for FBE powder curing. The coating process employs SJ-90/30 single screw extruder, 55kW for adhesive application and SJ-120/38 single screw PE extruder, 400kW, max output 1200 kg/h for the top polyethylene layer. Both extruders feature 38CrMoAlA nitrided steel screws with nitriding depth of 0.4-0.7mm and hardness exceeding HV740. The FBE spraying station uses multi-gun electrostatic spray with redundant (n+1)x2 design, achieving over 95% powder recovery rate.

Control is managed through internationally recognized PLC with 10-inch industrial-grade HMI, supporting recipe storage for one-click diameter changeover. VFD options include internationally recognized brands with industrial-grade electrical control components. Cooling uses water spray quench at <=20deg C and >=0.3MPa with 26-30 m3/h flow rate. End beveling uses a rotary peeler knife completing each end in approximately 40 seconds with kraft paper masking. Final inspection includes high-voltage holiday detection and thickness measurement. The line requires 4-5 operators and workshop height of no less than 9 meters for large diameter configurations.

Applications

This coating line is specifically suited for:

• Super-large diameter water diversion projects, coastal power plant cooling water lines, large-scale municipal drainage and flood control

• Oil & gas transmission and distribution pipelines

• Municipal water supply and sewage pipelines

• Chemical plant process piping

• Mining and slurry transport pipelines

Target Market: China, India, Southeast Asia, large-scale water infrastructure projects

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

Established in 2003, Qingdao Huashida Machinery Co., Ltd. has grown over two decades into a leading high-tech enterprise specializing in pipeline anti-corrosion and pre-insulation equipment. Headquartered in a 33,000 m2 industrial park in Chengyang District, Qingdao, the company integrates R&D, manufacturing, marketing, and global service under one roof. With over 100 employees including 4 senior engineers, 15 mechanical engineering technicians, and 12 installation and commissioning specialists, Huashida combines deep technical expertise with practical field experience.

The company holds 58 invention patents, 38 utility model patents, and 38 software copyrights, reflecting continuous innovation in pipeline coating technology. Core technology originates from Germany, strengthened by R&D partnerships with Beijing University of Chemical Technology, Qingdao University of Science and Technology, and Qingdao University of Technology. For clients in the China, India, Southeast Asia, large-scale water infrastructure projects market, this means access to German-engineered technology backed by Chinese manufacturing efficiency and comprehensive after-sales support.