Monday 12, September 2011
BlueSky BlueLock Overlayed Clamp Joint hubs
History
In late 2008, we received virtually simultaneous reports from three SAGD plants on the premature leakage of clamp connectors. Samples of the failed hubs and seal rings were sent to a laboratory in Calgary for failure analysis. One major producer opted to perform their own failure analysis and shared the results with us. The results of the analyses demonstrated that two factors contributed to the premature leakage of the clamp connectors. The first was movement between the seal ring and the hub, which may be due to incomplete assembly of the clamp connector. The second is due to precipitate build up at the seal ring/hub interface, which caused localized aggressive corrosive attack at the critical sealing surfaceresulting in
premature leakage.
Leakage Not Brand Related
Below are three cases at different plants that conclusively prove that this premature corrosion-based leakage is not brand related.
First SAGD Plant Scenario:
They have two identically designed steam generators constructed by the same company using the same feed-water and operating at the same pressure
and temperatures. Both steam generators were supplied with BlueSky BlueLock 
clamp connectors. One steam generator has not had any leakage issue during more than two years of continuous operation, whereas the other is experiencing chronic premature leakage. The operators tried a competitor’s hubs at the problematic steam generator with the same results. Although it is difficult to verify, the only possible explanation as to what is happening here, is that the pipes have more inherent misalignment that is preventing the joint from being fully assembled, leading to premature leakage. This plant also has clear evidence of localized aggressive corrosive attack at the critical sealing surfaceresulting in premature leakage.
This site has since approved the installation of Inconel 625 Overlayed BlueLock hubs in their steam generators.
Second SAGD Plant Scenario:
Reported premature failure and sent product to us for analysis in late 2008. Shortly after that, they tried different seal ring materials, as well as a competitor’s connectors in an attempt to solve this problem. They reported that these trials had little to no effect and they were still experiencing premature failures. This site admitted to having severe misalignment and that fully assembling the clamp connectors was problematic. Currently, this producer is paying more attention to the assembly of the clamp connectors, has switched to BlueLock Inconel 625 Overlayed hubs, and has specified these on their next expansion….
Additionally, at this plant’s request, BlueSky has developed an all-metal seal misalignment compact flange, which they will also try by installing 18 full assemblies in their OTSG (Once Through Steam Generator) in the near future.
Third SAGD Plant Scenario:
This plant reported a three to six month span between failures of the clamp connectors. At this point, they contacted us and BlueSky recommended that they install Inconel Overlayed hubs in their OTSG. This client was the first site to install this solution in February 2010 and has reported that 20 months later (as of August 2011) the hubs were in the “as new” condition. They have purchased Inconel Overlayed BlueLock hubs for their Phase 2B expansion.
Although a few SADG sites do not currently use BlueLock clamp connectors, they also report premature and chronic failure of the competitor’s clamp connectors.
Attached is a drawing of the BlueLock Inconel Overlayed clamp connector for your review. We strongly urge you to replace the hubs in the problematic areas to this BlueSky Process Solution. If you have any questions or comments, please contact Jim Wheeler at jwheeler@blueskyprocess.com.
Best Regards,
Zvonko Milanovic
Vice-President of Product Development
BlueSky Process Solutions
Corporate Sales Office
Phone (514) 428-5900
Cell (514) 246-6958
Toll Free Sales 1-866-643-5999
