Heatexchanger retube works are specially important subject for big industrial plants such as oil refineries, petrochemical industry, power plants, other chemical industries. For Shell and tube heatexchangers , Condensers, Feedwater heaters generally retube work is more economic according to manufacture the new equipment. Because you save the tubesheet , buffles and the Shell.
Old heatexchangers retube work seems maybe more simple and ordinary work , but actually it is not. Even it is different and complicated work according to making new heatexchanger. Because for to use the old heatexchanger tubesheet you must retube and pull the old tubes and stubs from the tube sheet without any damage on the surface. This work needs experiment and true echanical equipment. Our company is one of the most experienced and Professional foundation in this sector. For example while tube pulling we use hydrauliv tube pull method. Fort his job we design some special and critic equipments ourself.
The connection between tubesheet and tubes are welded or tube expanded. İn some high pressure critic service for to prevent the leakage groves are opened inside the tubesheet holes. Pull out the old tubes without any damage on the tubesheet is the most critic section of retube work. Traditional and wrong method is disproof the tubeexpanded tubes by drilling method and sometimes pushing the tubes with stroke method. We can list the disadvantages of this method as written below;
- İn this method the possibility of damage the tubesheet holes is high. Dimension and surface corruptions can be occured. This is a critic situation and shorten the heatexchanger service life.
- Cleaning time of tubesheets are slow. Not suitable for urgent shutdowns.
- İn this method you must seperate the tubesheets and all buffles. This situation cause time loose while disassembly and assembly steps of the heatexchanger.
Advantages of the hydraulic pulling method:
- This process is a method that catchs the tube inside the tube hole and pull out . By this way there is no mechanical contact inside the tubesheet hole. That prevents the protection of original tube hole dimension and circular shape. This method guarantee the quality.
- Don’t need to cut the tubes between baffles and behind the tubesheets , we generally pull the tubes both 2 tubesheets . This prevents perfect time advantage while the disassembly and assembly process.
- This method is perfect for planned small time urgent shutdowns of the industrial plants.
For retubing works one of the most important subject is cleaning and sensitive measure of the tubesheet holes with calibrated measurement equipments. For to prepare perfect tube expansion you must well know the dimension of tubesheet holes and calculate the optimal expanded ID (İnside diameter) of the tubes changes according to working service,tube material, thickness.