Transportation And Storage Of FBE-Coated Steel Pipes

The transportation and storage of Fusion-Bonded Epoxy (FBE)-coated steel pipes are critical links in ensuring their corrosion protection performance. Although FBE coatings exhibit excellent corrosion resistance, they are relatively brittle with poor impact and scratch resistance, and are sensitive to ambient temperature, humidity, and mechanical forces. Therefore, standardized transportation and storage management is essential to prevent coating damage, aging, or structural damage to the pipes, thereby ensuring the effectiveness of subsequent construction and long-term operation. Below are the specific operational specifications:

1. Preparation Before Transportation

Before transportation, coating quality verification e protective pre-treatment must be completed to minimize the risk of damage during transportation:

1.1 Coating Quality Re-inspection

In accordance with GB/T 39636-2020 Technical Specification for Fusion-Bonded Epoxy Powder External Coatings on Steel Pipes, re-inspect the coating’s appearance (no pinholes, bubbles, or peeling), thickness (single layer ≥ 300μm, double layer ≥ 600μm), and adhesion strength (≥ 10MPa). Non-conforming products must be repaired before transportation.
Conduct a comprehensive inspection of coating integrity using a spark tester (15kV voltage) to ensure no leakage points (inspection speed ≤ 0.3m/s).

1.2 Protection of Pipe Ends

Fit plastic protective caps (HDPE material, thickness ≥ 3mm) on both ends of the pipes (beveled or flat ends) to prevent foreign objects from entering the pipe interior and avoid collision damage to the coatings at the ends.
For flanged pipes, cover the flange sealing surfaces with anti-rust film + rigid protective covers to prevent scratches or rust on the sealing surfaces.

1.3 Selection of Packaging Methods

Choose appropriate packaging based on the pipe specifications (length, diameter), with the core goal of preventing friction and collision between pipes:

Steel Pipe Type	Packaging Method
Short pipes (≤ 6m)	Bundled with steel strips (strip width ≥ 30mm, ≥ 3 bundling points). Place rubber pads or non-woven fabrics (thickness ≥ 5mm) between each bundle of pipes.
Long pipes (> 6m)	Fixed with dedicated frames (steel or wood, with soft liners attached to the inner sides of the frames). The load capacity of a single frame must not exceed the design limit.
Small-diameter pipes (≤ 200mm)	Insert into dedicated plastic pipe sleeves (length ≥ 100mm) to avoid direct contact between pipe orifices.

2. Transportation Process Control

During transportation, focus on preventing mechanical impact, friction scratches, and environmental erosion. The specific requirements are as follows:

2.1 Loading and Unloading Specifications

Utilizzo specialized lifting equipment exclusively: Prioritize hooks and slings (width ≥ 100mm) with soft liners (rubber or nylon). Direct bundling of pipes with steel wire ropes is prohibited (to avoid indentation damage to the coating).
Control the loading/unloading speed at ≤ 0.5m/s. Throwing or impacting is prohibited. Pipes must be kept horizontal when lifted to prevent coating scratches caused by tilting.

2.2 Transportation Vehicles and Fixation

Utilizzo flatbed trucks or dedicated tank trucks. The truck bed must be paved with non-slip rubber sheets or wooden pads (thickness ≥ 10mm) to prevent pipe sliding during transportation.
Pipe fixation methods:
- For bundled short pipes: Secure them with steel strips + soft pads (a second round of fixation). Place non-woven fabrics between the steel strips and the coating to avoid direct metal contact.
- For long pipes in frames: Fix the frames to the truck bed with bolts, and secure the pipes inside the frames with wedges (wooden, with soft liners attached) to prevent displacement due to jolting.

2.3 Environmental Protection Measures

Transportation in rainy weather: Pipes must be covered with rainproof tarpaulins (PVC material, thickness ≥ 0.3mm). Ventilation holes (1 hole every 5m, diameter ≥ 50mm) must be reserved on the tarpaulins to prevent condensation accumulation in the truck bed, which could dampen the coating.
Transportation in high temperatures (ambient temperature > 35℃): Cover the top of the truck bed with sunshade nets to avoid prolonged exposure of the FBE coating to sunlight (which accelerates coating aging).
Transportation in low temperatures (ambient temperature < 0℃): For long-distance transportation (> 24h), provide preheating protection for the coating surface (cover with thermal insulation cotton to prevent coating embrittlement due to low temperatures).

2.4 Transportation Routes and Speed

Prioritize smooth highways and avoid bumpy roads (e.g., unpaved roads, potholed sections). Maintain a driving speed ≤ 60km/h (≤ 80km/h on highways). Decelerate gently when turning or braking to prevent pipe impact caused by sudden stops.

3. Storage Management Specifications

The storage of FBE-coated steel pipes must meet the requirements of moisture prevention, pressure prevention, and corrosion prevention. Strictly follow the following standards for storage sites and stacking methods:

3.1 Requirements for Storage Sites

The site must have hardened ground (concrete or asphalt, flatness tolerance ≤ 5mm) with a drainage slope ≥ 3‰ to prevent water accumulation from soaking the pipes.
Keep away from corrosive environments: Prohibit placement near chemical industrial zones, salt spray areas, or sewage ditches. Set up guardrails around the site to prevent unauthorized mechanical access.
Environmental control for the site: The storage temperature should be -5℃ ~ 35℃, with relative humidity ≤ 85%. For long-term storage (> 3 months), build sunshade sheds (top height ≥ 4m) to avoid direct sunlight and rain erosion.

3.2 Stacking Methods and Load Control

Bottom support: Use wooden or concrete support blocks (height ≥ 200mm, spacing between supports ≤ 3m). Attach soft liners (rubber, thickness ≥ 10mm) to the top of the support blocks. Direct placement of pipes on the ground is prohibited.
Stacking height:
- For pipes with diameter ≤ 500mm: Maximum stacking height ≤ 5 layers, with rubber pads (thickness ≥ 5mm) placed between each layer.
- For pipes with diameter > 500mm: Maximum stacking height ≤ 3 layers. Mark the bottom-layer pipes separately to prevent long-term compression deformation.
Stacking spacing: Pipes of different specifications and batches must be stored in separate zones with a spacing ≥ 1m between zones. Install identification signs (indicating specifications, production date, and coating type) for easy management.

3.3 Maintenance for Long-Term Storage

Regular inspections: Daily check the coating appearance (for scratches or bubbles); weekly inspect whether the support blocks are deformed or the ground is waterlogged; monthly conduct random inspections of coating integrity using a spark tester (sampling ratio ≥ 5%).
Environmental regulation: Strengthen ventilation during the rainy season (open the side curtains of the sunshade shed). In winter, if the site temperature < -10℃, provide intermittent preheating for the pipes (use a hot air blower to blow the coating surface, controlling the temperature at 10℃ ~ 15℃ to prevent coating embrittlement).
End protection: If the plastic protective caps fall off, replace them immediately to prevent dust and moisture from entering the pipe interior and causing internal rust.

4. Common Issues and Emergency Handling

4.1 Coating Scratches During Transportation

For minor scratches (scratch area ≤ 30mm²): Upon arrival at the destination, immediately repair using a special FBE repair agent (two-component liquid epoxy). Follow the process: grinding → cleaning → application → curing. Conduct a spark test after repair.
For moderate scratches (scratch area > 30mm²): Mark the location, prohibit use, and contact the manufacturer to send professionals for on-site repair or return the pipes to the factory for handling.

4.2 Coating Blistering During Storage

Cause: Mostly due to site humidity and water ingress between the coating and the substrate.
Handling: Cut open the blistered area, remove moisture and rust, re-blast the surface (to Sa2.5 standard), apply FBE powder, and test the adhesion strength (≥ 10MPa) after curing.

4.3 Pipe Deformation

For slight bending deformation (deformation ≤ L/1000, where L is the pipe length): Straighten slowly using a dedicated straightening machine, and re-inspect the coating integrity after straightening.
For severe deformation (deformation > L/1000): Classify as scrapped and prohibit use.