To increase the lifespan of your pipeline, you should have it concrete weight coated. The process for coating a pipe with concrete weights is dependent on the climate in which it will be used. For hot climates, pipes are wrapped in plastic foil. For colder climates, pipes are stored in special curing cabins. These cabins have vaporized water or steam injected to speed up the process.
Specifications
A pipe can be coated in concrete weight if it is made of steel or a similar metal. However, it should be protected during all phases of the work. This is because the internal coating must be able to withstand the concrete weight coating. Therefore, the Applicator must thoroughly inspect the pipe and note any damage in the inbound tally. Once the pipe has been coated, it must be stored properly to avoid damaging the concrete or causing deflection.
Concrete weight coating is an effective way to protect a pipe, such as the ASTM A335 P9, from corrosion and harsh environments. It is also highly effective in protecting the pipe from mechanical damage. It can also be used in conjunction with thermal and anti-corrosion systems. It is possible to use a concrete weight coating pipe in varying densities, depending on the requirements of the project. It is manufactured in an automated batching plant and applied by impingement or compression. It can be reinforced with wire meshes, cages, and jip cranes.
To measure the thickness of the concrete weight coating pipe, the CONTRACTOR must paint a stencil inside the joints. The stencil should contain information such as concrete coating thickness and density, as well as the measured weight in the air. The contractor must also propose a color-coding system for the different levels of concrete thickness. The concrete weight coating pipe should be marked inside one end of the pipe for ease of inspection. This is a vital step in concrete weight coating pipe applications.
Application
A contractor applying concrete weight coating to pipes must apply the material in the proper sequence. The coating must be applied to reinforced areas to protect the pipe from damage. If the coating is not applied properly, it may result in spalling. To prevent spalling, repair the pipe before applying another coat of concrete. To ensure proper installation, prepare the pipe surface by removing all loose materials. Once the pipe surface has been prepared, apply concrete weight coating according to the manufacturer’s instructions.
The concrete weight coating process varies according to the climate. In warm climates, concrete weight coating pipes are wrapped in plastic foil, while in cold climates, concrete weight coating pipes are stored in specially designed curing cabins. In both cases, steam or vaporized water is injected to speed up the curing process. The company’s experienced technicians will know how to use these cabins. A concrete weight coating application requires special tools to complete the job correctly.
A concrete weight coating plant uses a concrete mix consisting of iron ore, sand, cement, and water. The equipment is equipped with a batch plant, which contains silos to store cement and weighing bunkers. The mixer is fitted with a sieving system, a belt for transporting between the bunkers, and a hopper for the application head. A concrete batch plant also comes with a reclaim system to reuse over-spayed concrete.
Costs
A concrete weight coating pipe is a method for securing pipes that have a high density. The concrete weight coating is applied to the pipe exterior surface 106 and extends circumferentially and axially to cover a substantial portion of each pipe segment. The coating does not cover the connectors 108, which are usually threads or exposed surfaces suitable for welding. The coating provides negative buoyancy, as a result of its high density.
A concrete weight coating pipe is made of a concrete mixture consisting of iron ore, sand, cement, and water. The concrete weight coating pipe is supplied with a batch plant that includes silos for cement storage, weighing bunkers, and belts to transport the mix between them. The ingredients are mixed by a heavy-duty mixer, and the resulting coating mix is dumped into the application head. Concrete batch plants also come with reclaim systems to recycle the over-spray material.
If concrete weight coating is needed for a pipeline, it is essential to use the appropriate type of reinforcement. Steel cages or wire mesh are suitable, and the number of layers required depends on the desired cross-sectional reinforcement. Reinforcing wire should be overlapping the concrete coating by at least 1/2″. The reinforcing wire will be cut flush with the concrete coating cutback. The process of concrete weight coating pipe requires two or more layers of reinforcing wire.
Requirements
The following are the requirements for the application of concrete weight coating pipe. The thickness of the coating must be between two and six inches. The thickness of the coating must be uniform across the pipe. There must be no excessive overlaps, and the reinforcement must be installed with a minimum of one-half inch of overlap. The reinforcing wire should be cut flush with the concrete coating cutback, and two layers of wire should be used for a two-thirds-inch-thick concrete.
In addition to the thickness of the concrete weight coating, the coated pipe must also be reinforced. The reinforcements can be steel wire mesh or cages. The number of mesh layers to be placed depends on the desired final thickness and cross-sectional reinforcement. All the equipment used for the concrete weight coating pipe must meet the required specifications. The cement must meet the latest revision of ASTM C-150. The applicator must ensure that the pipe is stored separately from the other weight-coated pipes, including the piping in the anode joints.
As the demand for petroleum products has increased, offshore oil exploration and development have also intensified. Offshore petroleum development requires harsh environments, deep seas, and severe climatic conditions. The Egyptian Petroleum sector imports heavy aggregates from massive iron ore for use in the concrete cladding of submarine petroleum pipelines. To achieve this, local concrete coating mix components must be suitable for application to the pipes. They must be strong enough to protect the pipes from impact and mechanical degradation.
Common Defects
When the concrete coating has been applied to a pipe, the process of application may produce certain defects. For example, the coating may contain pinholes that appear as small bubbles or craters on the surface of the pipe. These defects can render the coating ineffective and render it nonfunctional. As a result, you should check your coating for these defects during the application process. To avoid these problems, make sure your Applicator performs thorough inspections and checks the pipe before applying the concrete coating.
Besides preventing corrosion, concrete weight coating can protect pipes against harsh environments and mechanical damage. It is applied over existing pipe coatings and can be used for pipelines with ODs of up to 48 inches. The formulation of the concrete weight coating is tailored to the desired density, typically 140 pounds/cubic foot. The coating can range in thickness from one to eight inches and has a compressive strength of up to 3000 psi. Reinforcing wire may be used to increase the strength of the coating.
A conventional concrete weight coating typically uses natural aggregate for its material composition. Although iron ore is an excellent choice for the coating process, it is relatively expensive and not available in some areas of the world. An economical concrete weight coating uses steel slag as a cement replacement. Steel slag does not have the cementitious binding properties necessary for pipe construction, but it is a cost-effective alternative to a traditional concrete coating.
Testing Methods
Concrete weight coating is commonly used in pipeline transportation systems. Its primary purpose is to enhance the on-bottom stability of the pipe and is useful in preventing slippage. It is applied to pipes with concrete thicknesses of up to 25 mm. Several methods were tested to determine their effectiveness. Read on to learn more about the different types of concrete weight coatings and their respective advantages and disadvantages. Here are some of the most common ones.
Before applying the concrete coating, the steel wire mesh position needs to be controlled. This ensures a certain wire depth during the coating process. Next, the pipe is weighed to ensure that the joints are constructed to the correct thickness. Finally, the pipe is cleaned to remove any extra wire, and the coating is allowed to cure for about 30 days. To ensure the best results, the concrete coating thickness must be measured to verify the specified requirements.
A sample of the concrete mixture shall be obtained at regular intervals for seven days or until specified values are reached. If the pipe is wrapped with polyethylene, the outer wrap will serve as a curing membrane and retain moisture in the concrete. A sample of the pipe must contain at least 150 square inches of cracks or 25 percent of the total thickness of the concrete. If the remaining concrete is sound, this portion of the pipe can be accepted without repair.