This post reminded me I needed to blow my tank out. I had replaced the original drain valve as well with a street ell, and ball valve with a hose barb for rubber hose. I opened it up and water came out, but the flow continued with water vapor, and then the flow stopped as the expansion of air resulted in ice forming in the drain line. I've noticed before that the water vapor will never really stop being seen. I'm assuming it is in the compressed air, and condenses out with the expansion.
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