3LPE Coating Line for Steel Pipe Anti-Corrosion DN114-820 mm
Overview
The DN114-820 mm machine is the mid-range workhorse of our anti-corrosion programme. It lays a three-layer polyethylene coating on the outside of steel pipe in a single continuous pass, and it is the model most often ordered by pipe mills and coating service companies whose order book mixes water pipe, city gas pipe and medium-size oil and gas transmission pipe. Because the conveyor, seal sets and die are sized for a practical range rather than a single diameter, one line keeps 4 to 32 inch pipe moving without a second investment. Field data from our own installations puts changeover between two diameters at roughly half an hour when the seal set is pre-staged.
Key Configuration
Blast chamber with 2 x 75 kW wheel units and abrasive recycling, rated 600 m2/h. Three-stage dust collection. Intermediate frequency heater with a liquid-cooled power unit that protects the coil and semiconductors at working temperature. Epoxy spray booth with filtered recovery and rotating sieve for fresh and reclaimed powder. Side extruder with 1,200 kg/h output on a 1000 mm T-die, plus a separate adhesive head. Helical gearbox, gear material 20CrMnTi. Screw and barrel in 38CrMoAlA, nitrided 0.4 to 0.7 mm, hardness above HV 740. Well-known brand PLC with HMI, four control cabinets in total for blasting, wrapping, bevelling and holiday detection. Conveyor driven by geared motors with speed control.
Main Equipment List and specification
| No. |
Name |
Specification |
| A. Surface Cleaning Equipment |
| 1 |
Steel pipe conveyor |
Adjustable speed and angle, pipe uploading and unloading controlled by PLC |
| 2 |
Shot blasting machine |
|
| 3 |
Cyclone dust collector |
High efficient downwind cyclone dust removal |
| 4 |
Impulse cartridge dust collector |
|
| 5 |
Centrifugal fan |
|
| 6 |
PLC control system |
Automatic control of the line |
| B. Coating Equipment |
| 1 |
Spiral pipe conveyor |
Adjustable speed and angle |
| 2 |
Induction heating machine |
|
| 3 |
Powder spraying device |
Spraying thickness 80-800μm |
| 4 |
Automatic feeder&dryer |
|
| 5 |
SJ-PE Extruder |
|
| 6 |
SJ-AD Extruder |
|
| 7 |
Adhesive extruder die mould |
High quality die steel |
| 8 |
PE sheet extruder die mold |
High quality die stee |
| 9 |
Adhesive/PE sheet coating device |
Pressing roller with silicon coating and internal cooling |
| 10 |
Environmental Protection Ventilation equipment |
|
| 11 |
Cooling Spray equipment |
|
| C.Platform Equipment |
| 1 |
Steel pipe platform |
High quality |
| D.Groove Equipment |
| 1 |
PE Beveling Machine |
Steel brush disk, |
| 2 |
Hydraulic Lifting and Turning Machinery |
For lifting and turning the pipe |
| 3 |
Hydraulic Equipment |
|
·One line covers 4 to 32 inch pipe; diameter changeover is a die and seal change, about 30 minutes, not a line rebuild.
·Three layers applied in one continuous pass: epoxy powder, copolymer adhesive and polyethylene, so the pipe is coated ·before it can oxidise again.
·Shot blasting reaches Sa 2.5 or better, then dust passes a three-stage collection chain so the blast chamber stays below the working limit.
·Coating capacity up to 800 m2/h with 95 percent powder recovery, which keeps consumable cost per metre predictable.
·Holiday detection runs before the pipe leaves the line, so a coating fault is found on your floor rather than at the trench.
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
Pipe arrives on the walking beam rack and is fed by lift-and-carry arms. Shot blasting removes mill scale and rust while a three-stage dust chain, settlement chamber then cyclone then cartridge filter, keeps the blast chamber clear. The pipe is internally air purged and both ends are masked with kraft paper. An intermediate frequency coil brings the steel to the coating window, epoxy powder is electrostatically applied, the copolymer adhesive is extruded through its own head, and polyethylene is laid on from the side extruder. Water spray cooling locks the layers, the joint is cut, the pipe end is bevelled, and a holiday detector sweeps the full circumference before unloading. Note that masking the ends with kraft paper cuts the later bevelling time to about 40 seconds a pipe against roughly two minutes on an unmasked end.
1. Pipe diameter: 118-820mm
2. Processing capacity: ≥250m2/h
3. Cleaning level: ≥Sa2.5
4. Materials for production: epoxy powder, adhesive, polyethylene
Standards Compliance
Coating is produced to GB/T 23257 for the domestic market, and to ISO 21809-1 or DIN 30670 where the buyer's contract calls for a European or international specification. The blast and preparation regime follows ISO 8501-1. To be precise about what we can and cannot assert: we do not claim that any specific oil company has approved us as a supplier. Where a project requires an operator-specific specification, we work through it line by line during technical clarification and confirm each clause against the configuration being quoted.
Applications
Water supply and drainage pipe; city gas distribution networks; medium-diameter oil and gas gathering lines; coalbed methane surface pipe; mine water discharge lines; industrial plant piping; pipe piles and structural tube. Buyers in this range normally run a mixed order book rather than a single product, and this configuration is chosen precisely because it absorbs that mix. It suits a plant producing between 30 and 120 km of coated pipe a year; above that, a dedicated large-diameter line is the better investment.
Service & Support
Installation and commissioning are supervised on site by 2 to 3 engineers over 15 to 30 days. Operators are trained until they can run and adjust the line without supervision. The documentation package is in English and includes layout, foundation drawings, electrical schematics, P and ID and machine manuals. A two-year spare parts package can be supplied with the line, and critical wear parts are despatched by air within 72 hours of a confirmed order. Warranty covers the main machine for 12 months and the screw, barrel, motor and gearbox for 24 months.
Why Choose Qingdao Huashida
The three-layer polyethylene line is one of the products that earned our place on the Shandong Province First-Set Technical Equipment list, a designation given to domestically developed equipment that replaces imported machinery. We hold 58 invention patents and 38 software copyrights, and we build our own control logic rather than integrating a third-party package, which is why the changeover recipe for each pipe diameter is stored on the machine and not in a technician's notebook. A coating service company in the United Arab Emirates has come back to us in three separate years for additional 3LPE capacity.
Your message must be between 20-3,000 characters!
