BLASTING & COATING

 All types of industrial and pipeline Coatings in Maintenance and new construction. Such as Tape Wrapping, All types of Liquid coatings, Concrete coating, structural coating, Tanks coating internal and external, Special type of coating etc..    

  This Method Statement is described to carry out abrasive blasting and coating works in shop and touch-up/repair works of weld joints in the field for Piping at Buildings, plants and refinery. 

 When a pipe has to be buried underground, we have to take extra care to protect its external surface. This is mainly due to the corrosive nature of the soil. The soil can be soft mud, sand, rocks, moisture, minerals, salt water, and so on. In this environment, the steel pipes will undergo severe corrosion. Some common types of corrosion anticipated in underground corrosive environments are provided below:   

General corrosion- The gradual destruction of pure metals by the action of air, moisture, or a chemical (such as an acid) on their surface. 

Pit­ting corrosion- A localized form of corrosion by which cavities or “holes” are produced in the material. 

 Stress corrosion- A type of environmentally-assisted cracking or the formation of cracks caused by various factors combined with the environment surrounding the pipeline. It occurs as a result of a combination between corrosion and tensile stress.  

 Microbiological corro­sion- It occurs due to the presence of sulfate-reducing bacteria. They convert sulfate in the soil to sulfide, which attacks steel, causing severe pits.To prevent corrosion, in underground pipes/pipelines, we use a coating. The coating is a barrier to protect steel from the environment. This is supplemented by a Cathodic Protection system in most cases. 

 Abrades surfaces of metal or hard-composition objects to remove adhering scale, sand, paint, grease, tar, rust, and dirt, and to impart specified finish, using abrasive-blasting equipment: Shovels or pours abrasives, such as sand, grit, or shot of specified grade into machine hopper. 

The use of segmented charge technology for blasting has become a very mature rock fragmentation technology. In this technology, the air gap is introduced into the explosive column by segmented charge, which is used as a common method to optimize rock fragmentation under a given charge length