Powder Flush was specifically designed to overcome the shortcomings power flushing has in cleaning microbore systems and I can assure you that it does NOT cause leaks and in fact causes less leaks because we don’t have to use strong acidic cleaners. The powder and pellets we use are by design, just hard enough to scrape of hardened sludge but not so hard that it can cause leaks or damage. We have various sized pellets of different densities depending on pipe size and age of the system we are cleaning. We have performed hundreds of procedures on microbore, both copper and plastic and have a much higher success rate than trying to power flush them. It is true that standard power flushing is not all that effective on microbore and it is true that Powder Flushing will get better results. We know this because around 50% of our work is on systems where power flushing has already failed to get results, at least once.