EN13849 Differences between Category B and 1

[MarcoVezzali]

So Rob, you mean that 1 feedback signal is enough for considering the system a Cat.3 (MTTF high and DC 90% this portion could reach PLd), don't you?

 

[Rob.]

The feedback will need to be in series through both valves. 

I don't know anything else about the architecture of your circuit. Or components used. So I couldn't say. 

It could be possible though. Only way to know for sure is to calculate it.