Do vent-valves stop working over time?

[peterp]

Had an issue with a board which popped after having no issues for months where it had occasionally been left in the sun after use for quite some time. One day it popped and when I unscrewed the vent-valve I tried blowing through the thing and could not get one bit of air to pass through it.

Would dust/salt-water over time cause it to mal-function over time and what specs should one look for when trying to find a replacement?