Correct, but I was only showing the effect of the actual flow & head required for a system and the actual flow& head for a given pump curve, the equilibrium or steady state point was only arrived at by doing a number of calcs until both balance out on that particular pump curve.
In "your" case above, the TRVs (if fitted to all the rads) will keep throttling in until the desired flow rate (based on the temperature demand) is reached and the pump head will increase (pump capacity decrease) to give this exact flow. If one had no TRVs fitted and then "1/2" the rads were shut off then the flow rate through the remaining ones will increase, the pump head will keep increasing and the pump flow rate (capacity) will keep decreasing....until the pump head and pump flow rate are equal to the (remaining) rads head & flow rate.
Copy & paste this link into google and it should open and then scroll down to the NXL NYL33 pump curves. (Edit: should open directly)
http://www.hagegroup.com/uploads/pdf/NXL.pdf
