I’m pretty sure that’s not what
@travlerajm is getting at because his contention is that tennis balls change their size to equalizer internal and external pressure, and that’s why his “venting” method can repressurize a ball within an hour whereas a tennis ball pressurizer takes two weeks.
My understanding is that if a ball is going to change volume to equalize pressure, it would obey PV=nrT And since the nrT side is constant, the pressure and volume linearly and inversely must change. The volume of a sphere is 4/3*pi*r^3 so even releasing the pressure from a new tube of balls should result in a visible size change. That’s when
@travlerajm brought up “pressure balance”.
I’m all for finding a faster way to repressurize balls since I only have one corny keg and using it for two weeks puts it out of commission for daily use unless I want to constantly be pumping it up, and my laziness won’t let me do that.