How long do predict before the United States goes hyper-inflationary, if ever? And why?

the fed would prevent hyper -inflation that is it's main purpose

I can be a pessimist, but I don't think the US will go hyperinflationary. There is some serious questions of drought. It is unlikely that there will be a mass sell off of reserve currency.

Actually, it would be serious problem for the US if people stopped buying our bonds, let alone selling off the ones they have.

The traditional argument against a sell-off is that it would crash demand in the US and all the countries exporting to the US would lose. However, China will undoubtedly risk a short term loss of 100's of billion dollars in their reserves in exchange for not having the US interfere with them getting control of Tawain. It would be worth it in the long run. With their mortgages skyrocketing I think the citizens of the US will be urging the government to get out of the South Pacific.

I don't think that will happen. We are going into a recession, recessions by definition are deflationary. Unless there is some kind of serious government corruption or severe supply shock of some kind inflation numbers should begin to decline. There is just less money in the system, think about all the money that the banks have lost and how much households have lost on their balance sheet. In order for inflation to happen money supply needs to increase substantially over a long period of time.

For one hyperinflation is "inflation that is "out of control," a condition in which prices increase rapidly as a currency loses its value. Formal definitions vary from a cumulative inflation rate over three years approaching 100% to "inflation exceeding 50% a month." The U.S inflation rate is about 4% for the past decade just like most of Europe.

If it does, I think it will be a combination of a bad hurricane season, and a bad corn/wheat harvest. Last time I checked, the Fed can't stop a hurricane.