@Manas, present a more reasonable scenario... I still find torture to be abhorrent and inhuman... but, in answer to your question: maybe... (I'm going to have to reflect a bit on it - because it is a tough question). The verifiability is certainly a key. Of course, in the case of the yellowcake Uranium claim that was tortured out of someone, the CIA went into Niger to verify the claim and came up completely empty handed... as in, there would have been corroborating evidence of shipments anywhere near the amount claimed - there wasn't any evidence, so we were pretty damn sure that the story was bunk at that point. But then, in their infinite wisdom, the Bush administration decided to trust the tortured information over the CIA intelligence. So - verification only works if you trust the verifiers.
The ticking bomb scenario is pretty specific... I don't believe there's been any cases of us actually doing that. Torture has been used for confessions and for larger "intel" - such as yellowcake and WMD... Once one says it's OK to torture, I imagine a pretty slippery slope. Heck, the government is already pretty far down that slope. If I were to say, yes, OK in that particular situation then how does it really change our policy? How many times, outside of TV shows, are you going to have someone in custody who knows something that specific, current and actionable?
OK... here's my answer. No. It shouldn't ever be pre-approved... it should only be like "justifiable homicide" where, after the fact, it is a defense that the torturer can put forward. To pre-approve is to normalize it as Standard Operating Procedure... and we know where that leads - as it lead us already at Gitmo and Abu Graib and other locations less well known.