Bialetti coffee maker pressure valve

The pressure valve on my Bialetti 6-cup Moka espresso coffee maker blew out after 1 month.

I have had another unit for nearly 30 years (it still uses the same replacement gasket and basket as the new one), and the pressure valve is still intact on that one.

I did not subject the new unit to more heat than the older one.

1) Can I re-set the valve (there were no instructions in the box)
2) If not, where can I get a replacement valve.
3) Why do you think the pressure valve blew out when the older one has never blown out?