A type V (5) PFD is a Special use, or windsurfing PFD.
Every time the PFD is worn
offshore PFD
Type, I, II, or III PFD
The activity network does NOT represent the time component of a PFD because it does not take account of resource constraints, which includes time. It identifies the tasks that have to be carried out and the order in which they have to be executed.
discard because they are unusable
Every time the PFD is worn
We do not know what you mean by "PFD", please do not use abbreviations. But the answer would be when the instructions for the "PFD" say it needs to be replaced.
wear it in shallow water and see if it floats- such as a swimming pooleverything...(PotatoSalad67 says) the best way to test it is to take it out on the water and try it in shallow waters.
Proper size and comfort. No PFD can help if you do not wear it.
Every time the PFD is worn
how many straps there are on the PFD.