As an expert sommelier and brewer, I can confidently say that using 1/2″ PEX tubing for a spigot is more than sufficient. The opening in the faucet where the water flows through is typically only 1/4″ in outer diameter. Therefore, the 1/2″ PEX tubing will easily accommodate the flow of water without any issues.
In fact, the flow restriction will likely be more dependent on the hose and vacuum breaker attached to the spigot rather than the size of the tubing itself. These components often have their own restrictions that can impact the water flow.
I have personally used 1/2″ PEX tubing for various spigots and have never encountered any problems with water flow. Whether it's for a garden hose, filling a brewing kettle, or any other application, the 1/2″ PEX tubing has always been sufficient.
To further emphasize the point, it is worth noting that PEX tubing is commonly used in plumbing systems and is known for its excellent flow characteristics. Its smooth interior surface allows for efficient water flow, making it an ideal choice for various applications.
1/2″ PEX tubing is more than enough for a spigot. The size of the tubing is not the limiting factor for water flow, as the opening in the faucet is typically much smaller. As long as the hose and vacuum breaker are properly sized and in good condition, you should not experience any issues with water flow.