When you say the valve failed, EXACTLY what is wrong. Does the tube still hold air? Is the stem with the small nut at the tip bent? Is the valve separating from the tube? Or what else is going wrong.

Bent valve stems are a common result of poor pumping technique, or being clumsy or brutish when removing the pump. It's a user error and easily prevented with some care, but usually doesn't prevent the valve from working. If the valve is breaking near the base, it's almost exclusively because of excessive force against the valve when pumping.

So if your questions aren't yet answered, please provide more specific details and people should be able to help.