Steel Pipe Coating Plant 1220-2540 mm Three Layer PE
Overview
When pipe reaches 48 to 100 inch, the engineering centre of gravity moves from coating to handling. A 24 metre pipe at 23.5 t cannot be accelerated and stopped the way a 12 inch pipe can, and a two and a half metre circumference cannot be fully reached by a blast wheel mounted above the pass line. This line is therefore specified from the pipe downwards: conveyor capacity first, blast chamber geometry second, coating stations third. It is normally bought as part of a new plant rather than as an addition to an existing bay, because the pit foundation for the blast wheels and the nine metre clear height are decisions that have to be made while the building is still on paper.
Key Configuration
Pit-mounted blast chamber with dual wheel units and moisture-separated abrasive circuit. Heavy lift-and-carry conveyor with motorised width and skew adjustment rated for 23.5 t. Bucket elevator, screw conveyor and three-stage dust collection. Induction heater in the 1000 kW class with a forced circulation cooling unit that protects coil, capacitors and semiconductors rather than the pipe. Twin 1,800 kg/h extruder set with a 1000 mm T-die, plus a dedicated adhesive head. Over-provisioned spray gun array with four redundant units. Rotary sieve for fresh and reclaimed powder, cartridge filters with pulse cleaning. Four well-known brand PLC groups for blasting, wrapping, bevelling and inspection. Foundation and pit drawings issued before manufacture.
3LPE External Coating Line, Extra Large Diameter Configuration — Technical Specifications
| No. |
Parameter |
Specification |
| 1 |
Model / Type |
3LPE external coating line, extra large diameter configuration |
| 2 |
Pipe Diameter Range |
DN1220 – DN2540 mm (48" – 100") |
| 3 |
Pipe Length |
8 – 15 m |
| 4 |
Pipe Wall Thickness |
Up to 25 mm |
| 5 |
Maximum Pipe Weight |
23.5 t per pipe |
| 6 |
Coating Structure |
Three-layer polyethylene; three-layer polypropylene available |
| 7 |
Coating Capacity |
Matched to project take-off, typically 400 – 600 m²/h |
| 8 |
Surface Preparation |
Shot blasting to Sa 2.5 minimum; Sa 3 on request |
| 9 |
Blast Chamber |
Dual wheel configuration sized for full circumference coverage in one pass |
| 10 |
Heating |
Intermediate frequency induction, 1,000 kW class, liquid-cooled power unit |
| 11 |
Extruder |
2 × 1,800 kg/h with 1,000 mm T-die and separate adhesive head |
| 12 |
Spray Guns |
Over-provisioned with four redundant units |
| 13 |
Conveyor |
Heavy lift and carry, motorised width and skew adjustment |
| 14 |
Workshop Clear Height |
9 m minimum; 10 m recommended for maintenance access |
| 15 |
Foundation |
Pit foundation required for blast wheel units |
| 16 |
PLC and HMI |
Well-known brand, with separate controllers for blasting, wrapping, bevelling and inspection |
| 17 |
Operators per Shift |
5 to 6 |
| 18 |
Scope |
Turnkey option: layout, manufacture, shipping, installation, commissioning and training |
| 19 |
Warranty |
12 months machine; 24 months drive train |
| 20 |
Certification |
ISO 9001; Shandong First-Set Technical Equipment award |
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 |
|
Designed around the constraint that actually stops large projects: at 48 to 100 inch, the pipe is heavy enough that handling, not coating, sets the cycle time.
Blast wheel units sit in a pit foundation, which is the only arrangement that reaches the full circumference of a two and a half metre pipe in a single pass.
Twenty metre plus station spacing and a 9 m minimum clear height are specified up front, so the building is designed around the line rather than the line squeezed into an existing bay.
Turnkey scope available: layout, foundation drawings, manufacture, shipping, installation supervision, commissioning, trial production and operator training.
Quotation follows the project take-off, so you pay for the capacity your contract actually needs instead of a catalogue rating.
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 is lifted from the rack and centred on the heavy conveyor, then advanced into the blast chamber where wheel units set below the pass line throw abrasive across the full circumference. Abrasive is separated and returned, dust passes the three-stage chain, and the pipe exits to inspection. After internal purging and end masking, the induction coil brings the wall to the coating window, epoxy powder is sprayed, the adhesive head extrudes the copolymer layer, and the side extruder lays polyethylene while the pipe turns on its own drive. Water spray cooling, joint cutting, end bevelling and a full circumference holiday scan follow before the pipe is transferred off line. On this size, cooling water consumption and the temperature gradient through a 25 mm wall are the two parameters the operator watches most closely.
1. Pipe diameter: 1220-2540mm (20-48 Inch)
2. Processing capacity: ≥250m2/h
3. Cleaning level: ≥Sa2.5
4. Materials for production: epoxy powder, adhesive, polyethylene
Standards Compliance
ISO 21809-1 and ISO 21809-2 are the usual reference points for three-layer and epoxy coatings on large transmission pipe; DIN 30670 applies in Europe and GB/T 23257 in China; projects in Russian-speaking markets are supplied against GOST requirements. Preparation of the pipe surface is to ISO 8501-1. Where a project cites an owner specification, we assess the clauses against the quoted configuration and report the deviations rather than implying blanket conformity.
Applications
Very large water conveyance mains, including the internal coating plus external three-layer combination used on long-distance water transfer projects; thermal power cooling water pipe; large-diameter gas transmission pipe; port and industrial bulk water lines; large diameter structural and piling tube where corrosion protection is specified. Many projects at this diameter combine an external three-layer coating with an internal coating, in which case the line is quoted together with the internal coating section and the pipe handling between the two.
Service & Support
Turnkey delivery covers workshop layout, foundation design, manufacture, shipping, installation supervision, commissioning, trial production and operator training. Two to three engineers are on site for 15 to 30 days, and the schedule is planned so that commissioning finishes before your first commercial order. Documentation is in English, covering layout, foundation, electrical schematics, PID and manuals. Spares ship by air within 72 hours of a confirmed order. Warranty: 12 months machine, 24 months drive train, and a two-year package of wear parts on request.
Why Choose Qingdao Huashida
Very large diameter work requires the factory to have done it before. We run our own coating plant group inside the company, so the line configurations we sell are the ones we operate, and a problem found in our production is fixed in the design before it reaches you. Our 3PE steel pipe anti-corrosion line is on the Shandong Province First-Set Technical Equipment list, and we hold 58 invention patents and 38 software copyrights. For projects in this diameter class we normally begin with a site visit or a detailed questionnaire covering building height, crane capacity, transformer rating, water supply and drainage, because those five items decide the design more than the pipe size does.
---FAQ---
Q: What is the largest pipe this line can coat?
A: DN2540 mm, 100 inch. Above that the configuration moves outside our standard range and we ask to be involved at the design stage so that handling and blast geometry can be engineered specifically.
Q: Do we need to build a new workshop?
A: Usually yes, and mainly because of clear height and the blast pit. If an existing bay has 9 m clear height and a floor area of at least 120 m by 25 m in a straight line, it can often be adapted, and we will confirm this from your drawing.
Q: How much water and power does the line consume?
A: The pipe is cooled from coating temperature by water spray, so consumption is continuous and we size the recycle and treatment system with the line. Power is quoted as installed load, and we recommend a transformer at 120 percent of that figure to cover cranes, lighting and auxiliaries.
Q: Can the same line coat pipe internally as well?
A: It can be supplied as a combined external and internal coating line. The internal section is quoted separately, and the pipe handling between the two sections is designed so that the external coating does not have to be re-done.
Q: How many operators are needed?
A: Five to six per shift. The extra person over a mid-range line is normally on pipe handling, because the crane cycle for a 24 metre pipe is longer than the coating cycle.
Q: How long does the project take?
A: Manufacture and pre-delivery testing take 60 to 90 days. Site installation and commissioning add 15 to 30 days, and for a new building we prefer to be involved about four months before the line is needed.
Q: What is the investment payback?
A: It depends entirely on your contract volume and coating price, so we do not state a figure in a catalogue. We will, however, work through the arithmetic with you using your own take-off, coating thickness and labour rate, and put the assumptions in writing.
Q: Is operator training included?
A: Yes. Training is included in the commissioning scope and continues until your operators can run and adjust the line without supervision. Training is delivered in English with drawings, and we can arrange Russian-language documentation.
Your message must be between 20-3,000 characters!
