Remove close nipple?

I want to remove a 1/2" NPT close nipple from a ball valve. Any tips? Am I screwed (pun intended)?

Edit: it would be preferred to save the nipple...

Heat the valve and nipple in the oven at 300. Dip the nipple in cold water which should shrink slightly and unscrew.

Do not read anything into this...

Good idea. Are there any parts inside the valve that wouldn't like such a high temp? I know the rubber on the valve handle probably wouldn't, but it can be removed.

I heat them with a torch to do the same thing (no apparent harm to valve), so I couldn't see a 300 deg oven to be any worse. Saving the nipple would be a real trick if it's also "stuck" on. There are ID wrenches for this, but it would cost more than a new close nipple, and odds of success would be slim. Your better off sucking it up, removing with a pair of vise grips, and save the more expensive valve (preferably lock the valve in a vise padded with some rags)

Boiling it for a few minutes should provide enough heat and should not damage it in any way. Then chill the nipple.

Channel locks on the middle of the nipple. Usually you can reuse it as the threads are only screwed up in the middle.

If you have two nuts that will fit the nipple, you and put them both on the free end and then with some narrow pliers, unscrew only the nut closest to the valve. I've done this many times. For this to work, you can only put the wrench on the inner nut. Here's a pic to demonstrate.

I use a pair of slip joint pliers with the jaws ground smooth and a thick piece of leather wrapped around the threads several times and vise grips on the valve. Same thing with the vise grips jaws ground smooth and a thick piece of leather. Works great.. no damage to either.

they make a tool to do that.
http://www.lowes.com/pd_331787-943-05212_4294822079__?productId=3228214&Ns=p_product_avg_rating|1

Thank goodness for this thread, it just saved me a bunch of time. I ended up using an extra locknut that I have an put a tee on after the locknut. Worked like a charm!