I have just taken my plenum off and have found that my PCV pipes seem to have a valve in them is this right?

yes fella thats right

http://en.wikipedia.org/wiki/Crankcase_ventilation_system

A crankcase ventilation system is a way for gases to escape in a controlled manner from the crankcase of an internal combustion engine. A common type of such system is a positive crankcase ventilation (PCV) system, the heart of which is a PCV valve—a variable-restriction valve that can react to changing pressure values and intermittently allow the passage of the gases to their intended destination (which nowadays is the engine's intake stream).

I think he knows what the valve is, but the actual pipes have a restricter thingy and what looks like a mini pipe cleaner thing if i remember correctly, but yes, it is supposed to be there...

thank you