My latest development in balanced valve exploration..

I used parts from my push button valve and switched around the inner workings.
Now, pressure acting on the piston is still balanced, though a spring pushes it open...untill enough pressure builds up on the low pressure side ( countering the spring) and the spring is compressed.
The valve closes.
Pressure on the high side ( inside of the reservoir) pushes equally on the two sides..while low pressure keeps it closed..So it remains untill the low pressure side drops beneath the required pressure to compress the spring and voila..the valve reopens..
That, ladies and gentlemen..is what we call a regulator.

Output pressure is determined by springforce.
I made a prototype...I'm very sure of the principal behind it, just not sure I can mount it inside of my " Old Shatterhand" cannon without leaks from high to low side.
But that is not important...I'll lathe a proper one later.
I won't use threads..just a plug with O-rings that fits snugly inside the chamber.
The pressure will keep it in place at the end of the reservoir.
( I stole that idea...

Questions?