Birddy

I'm sorry but you are wrong.

In Illinois, the Il Dept of Ag oversees the inspections of NH3 equipment. If you are a farmer & have your own stationary supply tank, you are inspected & held to the same standards as any fertilizer dealer. 

Yes, valves, hoses, safety equipment (breathing masks etc) have to be replaced at dates specified by the mfg, usually stamped on the equipment. Your site for placing the tank has to be approved even before you start construction. You will be inspected at least annually, perhaps more often.

The inspectors are fine people to work with. They don't come on to your farm to shut you down, they come to make sure you are following regulations. They help point out issues that may not be disqualifying, but may need attention for the good of everyone. They want to keep you going and try to help you avoid problems. If you have some item that's out of date, they will point that out and ask that you notify them immediately when it's replaced, or repaired. This includes your tank and your wagons. 

If all is good, they issue an inspection report showing what all was inspected and that you are in 100% compliance.

To be fair about it, they don't show up in the middle of your "go" season & cause trouble. They'll visit in the off-season (whatever yours is) and perhaps point out something that is going to expire within the next few months & that you should replace it before  you get busy. They try to help you keep legal, not just show up to cause trouble.

They may leave your farm and go to a mega-dealer just down the road. Same inspections.