Today, I spoke with a representative of Sure Marine (Ballard/Seattle), regarding QEST fittings, resources and ways to connect new products to QEST tubing. Here's what he had to share:
1. Tubing transporting HOT water will likely fail before cold water (all other conditions same)
2. Tubing bent to accommodate a curve will likely fail before tubing that is relaxed and normally straight.
3. When cutting QEST, ensure one uses a tubing cutter that circulates around the tube, (similar to a copper pipe cutting tool), for one seeks a perfect 90-degree angle cut.
4. Once cut, use SEA TECH connections, which require the 90-degree perfect angle...and he said, always push tubing "home" till it meets the connectors internal fitting seat.
www.suremarineservice.com
I have not checked to determine if my QEST sized tubing matches what Sure Marine has in stock.