Why is the BOV/DV/R35/R55 relieving pressure when I pressure test it on the bench?
The first question would be do you have pressure going to any of the control ports such as Port A or Port B? Please refer to the FAQ for the proper Boost Leak Test Procedure.
If you do not have pressure applied to the control ports at the same time that pressure is being applied from the charge piping and the BOV/DV is opening, then it is functioning properly. You will need to apply the same pressure to the control ports.
Some notes that you may find helpful are below:
If you apply pressure to only Port A it will open around 20-25 psi
If you apply pressure only to Port B it will open around 40-50 psi
If you apply pressure to both Port A + B it will not open even past 200 psi
Using a solenoid as an output channel of a standalone, this is how some creative people are using low boost launch control with a minimum boost of around 7 psi. On the bench there isn't much airmass so 10 psi sounds about right, with the air mass/weight a turbo makes in a system it is right around 7 psi that you have a self-regulating pressure.