I have a shallow well , I have a check valve ( brand new) , b ut I don't know if I have a foot valve. My pump will hold pressure , for an hour but after that she unprimes , I've changed the pump and all the piping in the house , I don't know what to do net ? Can you help me ?

A foot and check valve perform the same function, They are both check valves.

My pump will hold pressure , for an hour but after that she unprimes , I've changed the pump and all the piping in the house ,
You've changed everything except the faulty check valve. Replace the check valve and seer if that doesn't solve your problem. Let me now if it helps. Good luck, Tom

Amen. I'm afraid you are going to find that you replaced everything except what needed to be replaced, which is the checkvalve.

I might add that, if the CV is leaking, you should notice pressure slowly and gradually falling over that hour, to the point that it finally hits zero.

Ive changed the check valve , the pump , put sealant and the gasket , sanded both end of the pump and injector , still awaiting on result because I broke one bolt this morning still pending

You better hope it's the check valve. The only other explanation would be a leak in the suction line and that requires you to pull the well point. Let me know what you find out. Good luck, Tom

Funky, how many pipes go into your well? Is it one or two? Also, check again on your pressure when you lose prime. Does it go to zero?

jlisenbe is asking what system you have, One or two pipes? See image,

It's a one line out , and so far the only thing to check is if there's is a foot valve or not , because I've change al the rest
So is a foot valve neccassary for a single line shallow well ?

So is a foot valve neccassary for a single line shallow well ? A check valve is a check valve no matter if it's installed next to the pump or at the well point.
Where's all this fixation on a foot valve coming from. If you have a working check valve installed next to the pump you don't need a foot valve. What I would do is open up the check valve and inspect it for any trash preventing it from closing. If the check valve's OK (and I know you don't want to hear this) I would be checking the suction line for a leak. Good luck, Tom