Originally Posted by kitten
That will be 1.5 t0 2 psi over ambiant pressure as it is maintained by a spring, so it will still be 1.5 to 20 psi over when under pressure from the water.
That doesn't sound right
The spring is mechanical so will press at a set rate linked to its compression more compression more force and any external forces will overcome the spring or increase the pressure as it can't adjust its self i.e. water on one side of the plate or even your finger
1.5-2.0 psi is very low, your cold water tap is normally 30-40 psi
If you walk into water with a pair of waders on think of the pressure on your lower leg
The above could be crap but may not be