KLINGER South Africa provides timely maintenance to Abengoa’s Khi Solar One’s solar plant valves. Tear down and refurbishment service for 63 valves.
As South Africa’s first and only thermal solar tower plant, Abengoa’s Khi Solar One (KSO) knew that they needed an immaculate strategy when it came to their planned outage for maintenance. Global supply chain shortages and challenging geography meant that a tear down and refurbishment plan would require all moving parts to work perfectly in sync, so that no link in the chain would cause delays.
KLINGER South Africa was up to the challenge. Under the guidance of Tommie Vogel, KLINGER South Africa’s Key Account Manager of Renewable Energy, the KLINGER team first visited KSO on site to develop a scoping plan, then conducted weekly virtual meetings with the KSO team in order to dissect every aspect of the project, from start to finish.
Contacts mentioned in the article:
Tommie Vogel, Key Account Manager for Renewable Energy at KLINGER South Africa
Keeping scope creep under control
This detailed strategy served the team well, when unexpected challenges arose partway through the refurbishment process. The initial scope of 48 valves soon increased to 63 valves, as a tear down revealed much more extensive wear than the team had originally anticipated. Four separate KLINGER locations pitched in to conduct both on-site and off-site refurbishment work to keep the project on track, returning the valves to a proper leak-free working state.
„The outage saw many unplanned challenges, but Tommie and the KLINGER team gave timely feedback and suggestions. By doing this, we had time to think about solutions, and to plan the extra work properly.“
Hein van Heerden, Maintenance Manager at Abengoa
Custom repair and improvements
KSO’s plant valves were at the end of their life cycle, so bonnet leaks were one of their concerns. KLINGER’s full refurbishment process uninstalled the valves, disassembled them, machined flanges and lapped seats, repacked glands, rigged and reassembled bonnets and hardware, and aligned and torqued the flanges and hardware. All valves were leak tested and documented.
Because the discovered level of valve wear required more machining than usual, KLINGER conducted a thorough material examination, and recommended a change of gasket hardness to provide a better match for KSO’s valve usage patterns. This presented an additional challenge to the KLINGER South Africa team, since getting the new gaskets to South Africa from India during COVID-19 restrictions was a tall order. KSO agreed with KLINGER’s suggestions for system improvements, and also requested assistance with additional machining, torquing and lapping for other flanges, beyond the original scope of the project.
Success through team work
The KLINGER team enjoyed their success, as Abengoa’s Khi Solar One started up the plant on time and leak free. After six months of successful operation, KSO requested that KLINGER return for their next planned maintenance outage, in April 2022. With a plan in place, KLINGER South Africa looks forward to the opportunity to again provide KSO with the high quality, punctual work for which the KLINGER team has become renowned.
Fact box
Solar superlatives
- The Khi Solar One tower is 205 meters tall and saves 183,000 tonnes of carbon per year.
- The Khi Solar One tower can reach a maximum operating temperature of 530 °C.
- The Khi Solar One plant covers 140 hectares in the Northern Cape Province, South Africa.
- The Khi Solar One solar field is made of more than 4,000 heliostats, for a total of 576,800 m2 of mirror surface.
Frequently asked questions (FAQ)
What is lapping?
Lapping is the process of machining or sanding the valve head and valve seat to ensure a leak-tight fit between the two parts.
How are valves tested for leaks?
After lapping, a blue dye is applied to the valve head and valve seat. The dry valve is actuated through several cycles, then inspected. Any areas where dye remains are low spots that aren’t sealing completely and thus need further work. This cycle of lapping and testing should be continued until no blue spots remain. Colloquially, this is known as a ‘blue test’.
How often should I lap my system valves?
System components experience wear based on a variety of factors, including valve construction, fluid media, and cycling time frames. Contact your KLINGER representative to discuss an appropriate inspection and maintenance schedule for your needs.
