Explosive welding presents optimal fabrication, maintenance and repair solutions for high-pressure vessels. With an almost naked-to-the-eye explosive process, this weld occurs at a speed of more than 8 000m/s and forms a permanent bond that delivers a host of benefits in comparison with other welding methods. Steinmuller Africa has offered explosive welding since 2012 and is the only company licenced and qualified in South Africa, both on-site or off-site, to offer this service to customers in the power generation, petrochemical, steel, paper, pulp and sugar and nuclear industries.
Explosive welding is a time-saving and cost-efficient method in comparison with other welding methods, as:
- Any combination of metals can be welded together, despite their dissimilarities.
- The detonation is completed within milliseconds, reducing welding time.
- During the detonation, the oxides between the metal layers are removed, resulting in a weld that has a true metallurgical bond.
- It requires one weld where conventional welding requires two.
- The bond does not require post-weld heat treatment.
- Welds are unaffected by thermal cycling which is crucial for high-pressure equipment.
- It prevents 99% of leakages, reducing the need for repair and maintenance.
Steinmüller Africa is currently the only company to offer tube to tube-sheet explosive welding and explosive tube plugging. Explosive tube plugging is a more specialised type of explosive welding, this is when a specialised plug is inserted in a tubesheet or header-type and then explosively welded to form a permanent plug for that tube. The company also offers 24-hour standby services for explosive tube plugging.
These technologies are most suitable for high-pressure machinery (eg, shell, tube, header- and tubesheet-type heat exchangers) to accommodate the high pressures involved and to prevent cracks from forming that may lead to downtime, injury or even death.
Power station heat exchangers
The company is called upon to assist in maintaining high-pressure heat exchangers at power stations, where equipment with extensive tube structures require plugging or welding during refurbishments. “Steinmüller is the exclusive explosive welding provider for several power stations as we are the only licensed and qualified company to perform explosive welding for the power generation sector,” says Friedrich Schwim, Senior Welding Engineer, Steinmüller Africa.
With a 30 000m2 facility in Pretoria, one-of-a-kind specialised machinery and a fully-fledged engineering team, the company continues to be at the forefront of technology and is currently developing two new welding processes while four new welding machines will be commissioned in the near future.
Friedrich Schwim
Senior Welding Engineer
Steinmüller Africa
friedrich.schwim@bilfinger.com
www.steinmuller.bilfinger.com
Explosive welding is the way to go