I've run flared aluminum lines for years with no problems. As stated before, support with clamps is critical, but there is also a reinforcement collar that goes on them right behind the flare to keep the vibration off of the flared end itself. How many people actually use them? Pump and regulator must be fixed, meaning, not swinging on the end of a piece of angle bracket. Lines should be supported 6" from the fittings, not 6 feet away.