[Joe] has already tested the pressure relief valve of his espresso machine. With the gauge in the way, [Joe] can’t make use of his frother, but a secondary valve could easily remedy that.

Meticulous is showcasing its smart espresso maker, which it says is the world’s first robotic lever espresso machine, at CES ...

[Ben Katz] is in the process of building a compact, closed-loop espresso machine ... gear pump that pumps the water through a heater. It’s a closed-loop system, so there’s a 3-way valve ...