Concrete Weight Coating
Concrete weight coating provides additional weight to an anti-corrosion coated pipe in order to provide negative buoyancy and mechanical protection for pipelines in subsea and wet sub-terrain environments. The weight of the steel pipe and concrete together ensure that the pipe will not float. Pipes coated with concrete are generally used offshore, river crossings and swamp crossings.
Solution:
The need to keep modern pipelines stable and safe on the seabed at economic price, led to an application of heavy low-cost concrete based on a relatively dry mix of iron-ore / sand / cement with a high specific weight. Basically two methods are used for this: the spray-impingement process ‘impingement’ and the wrapping process ‘compression’.
Key Features:
- Substantial additional weight accomplished with relatively cheap concrete materials.
Benefits:
- Negative buoyancy of submerged pipe.
- Enhanced protection by a strong mechanical protection layer.
- Pipe stability on the seabed.
How It Works:
Pipes that have already received an anti-corrosion coating are brought to the inspection station. Here they are inspected for damages (and repaired if necessary), weighed and registered. Then the pipe is brought onto either a rotational belt conveyor or onto a buggy system with pipe rotator and moved along the concrete application spot.
There are two main concrete application methods:
- Impingement: this method uses fast rotating drums to spray the concrete mix on the pipe with high impact. As concrete reinforcement pre-fabricated steel cage is pulled over the pipe prior to impingent.
- Compression: in this method concrete is wrapped around the pipe along with a temporary outer layer of plastic foil. As reinforcement a steel wire mesch is wrapped on the pipe during concrete wrapping.
The concrete is prepared and mixed on-line by means of a fully equipped weighing, dosing and mixing system.
After concrete application, the pipe ends are cleaned, the coated pipe is weighed and hereafter brought to an curing area. The curing area can either be a steam enforced enclosed area, which is usually the case with impingement coating, or an outside (sheltered) storage location, until the concrete has sufficiently cured.
When curing has been completed, the pipe will be cleaned, unfoiled (in case of compression coating), inspected, marked and brought to the storage location.
The Full Scope:
Selmers engineers and provides the technology for both the impingement and compression processes, including technology for pre treatment, post treatment as well as ancillary technology such as concrete mixing and sacrificial anode fixation. A typical scope includes:
- Pipe inspection, cleaning, weighing, handling and conveying equipment
- Reinforcement cage production and fixation system for impingement process or reinforcement wire-mesh wrapping system and enclosure foil systems for compression process
- Impingement or compression application equipment
- Intermittent pipe coating process equipment or continuous pipe coating process equipment
- Batching or continuous concrete mixing, concrete transport and reclaim equipment
- Steam curing or foil curing of coated pipe
- Sacrificial anode fixation
- Concrete coating testing and repair equipment
- Plant automation, pipe tracking software
Product Range:
The CWC plant solutions that Selmers provides are typically suited for
- Pipe diameters until 60” diameter (1524 mm)
- Lengths of 40 ft (12.2 meters)
- Bare pipe weights until 15 tons, coated pipe weights until 40 tons
Capacity and configuration of the plant will be well-engineered to the desired number of pipes per day for output.
Filterable Properties:
At Selmers, we specialize in advanced industrial machinery and automation for coating and handling pipes and tubes. With over 50 years of experience, we have grown into a trustworthy supplier of numerous automated solutions. Collaboration is key to creating real magic. Interested in optimizing performance and reducing risks?
