Is there a way to deact the E-stops from the flexpendant like in kuka robots?

Hi Alejandro

There are no built in methods that I am aware of.
On another note why would you need to? It could be dangerous if someone wants to E-Stop the machine and reaches for that stop button only to find out it doesn't work.
I imagine that disabling an E-Stop also voids any relevant warranties on the equipment too. 
The only way I can think of if you really need to would be to modify the internal wiring although again this would void warranties and I don't think you'll find anyone on this site recommending it. 

Perhaps just covering it up somehow with a hard case would work best so it can't be seen and no one tries to use it.

Good Luck,

Harry