May be you can send your shop floor technician to visit the yard with our QA inspector to solve the first case so our staff could handle this onsite on your behalf.
I think we could help solving the problem but what we don’t know is the root cause of the problem either it’s because of the valve itself or the way CUEL handled and stored them before taking out and re-test it. Another doubt is the warranty issue, is it still under MRC Singapore warranty and at whose expense ?