[craigcd]

Correct me if I’m wrong, but there is no rule in the pneumatic section for the robot build that states that the valves must fail open so the pressure in the cylinder is released after the power is off. The rules do not restrict the 3 position center blocked valve. If you go for the strict interpretation of the rules then all 2 position valves are illegal because the "working pressure" cannot be relieved at the pressure relief valve.