Does anyone know how to measure the pressure of the V-shaped leaf
springs used in vacuum or pressure regulators?  The plans say use an
8-inch 12-pound spring.  I have a box of springs; do I just find three
that are 8 inches long?

How is the pressure adjusted, once the springs are installed?  Is this
done by changing the point where the vacuum starts to spill?  Or is it
done by bending the springs?

Julie Porter