UffyBrass In-Line Air Flow Regulator Control Tool Valve 1/4" NPT (2)

Can this be used for fluids? I have an electric weed sprayer that runs 80psi and I need to reduce to about 40psi, it sprays so hard the fluid atomizes

would this work to limit air flow so you could use a free flowing line to inflate a kayak or zodiac?

thread size?

are these free flow one way and controlled the other