Concrete weight pipe coating
Concrete weight coating (CWC) involves extremely high operational costs for coating materials (iron ore and cement). Therefore a controlled execution of the coating process from the start of production is essential.
Bauhuis has in-depth knowledge of the process and brings experiences gathered over 40 years in designing concrete weight pipe coating equipment to the table. Bauhuis can supply impingement as well as wrap technology based concrete weight pipe coating plants along with Cage and/or Wire reinforcement.
- Pipe sizes between Ø8 and Ø56 inch
- Pipe lengths from 26 to 60 ft (8 to 18 meter)
- Output up to 400 metric tons per hour
- Densities from 2250 to 3400 Kg/M3
Concrete weight pipe coating equipment
Specifications taken into account when designing the concrete weight pipe coating equipment are API 5L 44th Edition, BS-1881, BS-12, BS 4027, ASTM C150, BS-882, ASTM C33, DNV-OS-F101/2000.
Impingement or Wrap coating
An impingement concrete weight pipe coating plant is where the concrete mix is being applied in a spray / impinging method utilizing high speed rotating rollers directing concrete to the rotating outer pipe surface from the top or side as it passes the application station.
A compression concrete weight or wrap coating plant is where the pipe is conveyed in a helical fashion past the coating applicator belt head forcing the concrete weight coating material together with wire mesh layers to the pipe wall from below. After the concrete weight coating is applied, the pipe is supported and taken onwards by rotating belt heads.
Bauhuis has introduced many innovations to the impingement plant design to improve the efficiency. Examples of these innovations are a continuous coating buggy carrousel system, an automatic mesh wire application machine and special cutback/anode shielding and reclaim system to minimize spillage and over spray.
Concrete batch plant
In order to prepare the concrete weight coating mix with the right density iron ore, sand, cement and water are mixed in batch plants supplied together with concrete weight pipe coating plant. Batch plants include silos for storage of cement, sieving and weighing bunkers, belts for transport between the bunkers and mixer and finally the heavy-duty mixer where all the ingredients are being mixed. The coating mix coming out of the mixer is dumped into the hopper right in front of the application head. Concrete batch plants come with reclaim systems for reuse of over spayed material and thus maximizing performance of the concrete weight pipe coating plant.
All concrete weight pipe coating requires reinforcement. These reinforcements can be steel cages (used only with the impingement system) or steel wire mesh or a combination of both. The amount of mesh layers is depending upon the final concrete thickness (up to 8 inch or 200 mm) and the required cross- sectional reinforcement percentage.
For installation of the anti-corrosion anodes onto the pipes to be coated Bauhuis supplies complete anode installation stations including rotators, jip cranes, welding set and back fill equipment.
Largely dependent on the climate the process of curing the freshly applied concrete weight coating requires specialized curing cells. In hot climates the pipes are in most cases wrapped in plastic foil and stored in the yard for curing. In cold climate condition the concrete weight coated pipes are stored in specially designed curing cabins where steam and vaporized water is injected to speed up the curing process. Bauhuis has in-depth knowledge on the design and building of these curing cabins.
Concrete weight pipe coating plant
External concrete weight coating of previously anti corrosion coated steel pipes provides negative buoyancy and mechanical protection. The thickness of the coating is depending upon the depth of the operational pipeline. There are two main types of concrete weight coating plants, impingement and compression or wrap plant.
The drawing below shows the standard design of a concrete weight pipe coating plant. Clicking on the pins(dots) will provide detailed pictures of the various pieces of concrete weight pipe coating equipment being part of the plant.
Zublin (cage) machine
Anode application station
Concrete application station
End treatement area
Concrete batch plant
Raw material area
Pipe handling equipment
As automated pipe handling is obligatory in most pipe coating plants, Bauhuis offers a wide range of pipe handling equipment. Solid mechanical designs are coupled with sophisticated power & control systems for remote “hands off” movement of the pipe through the plant.