I stock a lot of fittings. They make a lot of thread sizes that fit the 1/2" tubing so you don't need to use reducers. There are a lot of other manufacturers besides Qest making fittings now like SeaTech snap-in fittings, Flair-it and others. The Flair-it as a very easy type to use, as is the SeaTech if you can find them.
Lew Farber...RVIA Certified Master Tech...ABYC Certified Master Marine Electrician
SOLAR TECH ENERGY SYSTEMS, INC.
AM SOLAR ...MAGNUM…VICTRON ENERGY...LITHIUM & LIFELINE BATTERIES…MARINE REFRIGERATION