Engineering services unit of Tose’e Pushesh Sazandegan Noavar Company pursues the following goals:
• Increasing volume of perlite ore using mobile furnaces
• Installing polyisocyanurate and cellular glass on pipes and sphere vessels
• Executing PIR and PUR in spraying and injecting types
• Establishing full automatic workshops in refineries
• Treatment of surfaces of up to 80 percent wall corrosion with composite
Corrosion is the main reason of metal destruction which is followed by enormous costs. The following subject which is published in the second number of composite journal mentions a reasonable method for confronting such phenomenon in gas transferring pipelines using composite sheets:
Supplying fuel is one of basic issues of every country and its cheap and secure transfer is a remarkable issue. One of the fast, secure and continuous ways of gas transfer (as a fuel) is using overall pipeline system. In some situations it is necessary that pipes pass salt marsh areas with high acidic characteristics or humid and corrosive areas. These conditions cause gradual corrosion and decay of the pipe.
In order to keep the pipe away from corrosive conditions and environment, methods like cathodic protection and coating of steel pipes surfaces can be implemented. But nonetheless, often happens that the pipe is corroded in a way that its thickness is lower than the safe design thickness.
In this situation, based on the traditional method the corroded part is removed from the line and substituted with a healthy pipe which needs cutting gas flow in the pipe, removing the corroded part and welding after substitution. In this way, some fuel is wasted and left in the workplace which occasionally leads to explosion in the welding process.
According to the mentioned problems and issues, considering a better method seems to be necessary. Reinforcing transfer pipes with composite material is a secure and cheap method (table 1).
Reinforcing with composite layers:
In this method composite layers with glass fibers are used. Angles of fibers and number of layers is calculated according to pipe’s pressure, design standards and extend of the corrosion. Also, suitable resin is selected and used due to chemical and thermal conditions the place.
Composite layers are prepared in textile form, Impregnated with resin in place and are wrapped on the prepared surface of the pipe with twist method and standard angles by expert workers.
1- Costs of welding and gas cutting are removed in this method.
2- This method is capable of returning corroded pipes to the original design situation and also keeps them from further corrosion.
3- Pipelines can work in their normal condition and pressure during the treatment and there is no need to cut the gas flow. Also, gas is not wasted in this method.
4- Due to low weight of composite materials, installation is easy and treatment is performed by two people without need to special instrument and equipment.
5- Time is also saved in this method because there is no need to cut the gas flow, chopping pipe and welding.
Table 1 shows comparison of these two methods. Presented numbers are based on costs of substituting 16 km pipe in traditional method and treatment of the same amount of pipe with explained method. This research is performed by Iran composite institute.
According to the above table this method is more reasonable than prior methods. The amount of saving has been remarkable. Considering that gas industry is developing in the country and gas is transferred to different regions, plus gas transfer line from Iran to Turkey has been launched and also gas pipeline from Iran to India is under evaluation, paying attention to this technology can save a lot of maintenance costs of pipelines for the country. This service can even be implemented for gas importer countries. Considering this method for maintenance of oil and water pipelines, if possible, can be useful and needs attention of the authorities in this regard and reminds performing more research.
• Automatic implementation of minor coatings
• Implementation of a variety of coatings by 360 degrees spraying devices
• Implementation of polyurethane coatings by AIRLESS spraying devices