Negative pressure for keg transfers?

[Vendetta]

It seems to me that you could employ a vacuum pump (modified bike pump?) to negatively pressurize a keg for small volume racking where you might otherwise use a positive displacement pump (but don't have one because it costs as much as an automobile). Top cropping yeast and racking from a barrel both come to mind as possible applications. Thin gauge and straight featureless sides on a keg are likely a dealbreaker, but is this a workable system?

[hops cynic]

Should work great if you want a keg full of foam.

[mishipeshu]

Vacuum transfer works fine on non-carbonated beer.

[Moonlight]

Why pump at all? Merely using pressure to push is pretty dang common.

[Vendetta]

Quite honestly, it never occurred to me to use this on carbonated beer, or for routine keg filling. I agree with Moonlight on this, and I don't generally pump or pull when pushing is an option. I just think there are a few situations where this might just do the trick. Obviously pushing is an option with a barrel transfer, but pulling seems like it might be a bit better to me (of course this would be done under a co2 blanket).