Heat Exchanger Fabrication/ Retubing / Tube-Plugging

Shell and Tube Heat Exchanger Repairing

There are many different type of heat exchangers, shell and tube, plate or spiral used in the industry depending on the application. The most widely used type is shell and tube. Shell and tube heat exchanger consist of shell and a bundle of tubes hold together with the support of tie rod and baffle plates. There is different type of tubes, for example, bare metal tube, finned tube, corrugated surface, or inner stared tube, depending on the applications, heat transfer efficiency or medium passes through.

After years of service and/or due to insufficient/ ineffective preventive maintenance, it is not uncommon to have significant drop in the heat exchanger heat transfer efficiency. This is usually attributed to scale depositing on the surface forming a layer of insulation, hence reducing the heat transfer efficient.

While on the opposite, instead of forming thick scale (layer of insulation), the tube wall might experience thinning due to corrosion/erosion taking place in the tube. This might results in by-passing/leaking or tube puncture. Initial mitigation would be tube plugging, however, in the event where the 5% of the tubes have been plugged, by rule of thumb, the difference in heat transfer would be noticeable already and the next course of actions shall be put into consideration: retubing/ new heat exchanger fabrication.

Tubular Heat Exchanger Re-tubing

Heat exchanger retubing meaning changing new tube to those leaking tube which aren’t repairable by tube-plugging. Retubing repairing works involved removing affected tube out from the tube-bundle and reinsert a new tube with same material construction, thickness, O.D. and length. Retubing can only be considered when the baffle and tie rod are in good condition. Again, there is a rule of thumb where retubing is favourable, which is when there is less than 10% of the total tube are affected. More than that, new heat exchanger fabrication or tube bundle fabrication is more highly recommended

Heat Exchanger Fabrication/ Tube-bundle Fabrication

A whole new heat exchanger fabrication includes replacing the shell and tube bundles all together. However, if the heat exchanger shell is in good condition, where most of the time it is, replacing a new tube-bundle itself is sufficient and more economical.

Heat exchanger tube-bundle fabrication meaning assembling a set of new tubes, an exact replica of existing unit. This can be done by fabricating new tube based on mechanical drawing, technical specifications which share all the information about the mechanical and material of for the tube bundle. However, in case this information is not available, we usually suggest pulling out the tube bundle and take all the necessary physical measurement on site to produce a new mechanical drawing of the said unit.

Then purchase the raw material: tubes, tube sheet, baffles, tie rods will be from our reputable suppliers from Korea/ China, where they fabricate based on the specification we provided. A joint QC inspection with customer before delivery could be arranged to ensure the quality is met. The assemble of tube bundle will then be done by our team of experienced technical personnel with over 20 years of experience.

With our hands-on and technical experience over the years, we believe we are the right solution provider to your heat exchanger problems, be it plugging, retubing or tube bundle fabrication. Please feel free to contact us regarding your HX issues and we will be glad to help.