Probably you'll have a different perspective about the significance of screwdrivers once you learn a little more about the history of technology.

To correct one misreading on your part, though, my claim was that the technology of distillation was developed in India (or possibly China), not the Sprengel pump. I too would be very surprised to find a medieval Sprengel pump from India or anywhere else.

I'm curious: would you also be so foolish as to claim that chemistry and physics have nothing to do with the pseudosciences of phlogiston, numerology, astrology, and alchemy? How about the steady-state theory of cosmology?

A vacuum tube is not based on "distillation" of anything. It operates with charge carriers in vacuum, with no phase change of any masses involved, whereas distillation involves liquid/gas transitions so it can't possibly have anything to do with the operation of a vacuum tube which is based on an arrangement of solid electrodes in a vacuum and the flow of charge carriers between them. As for the history of technology, I'm moderately familiar with it and I don't see the relevance here. If absolutely everything you touch when creating something were relevant for the question of "Have you an example of a western invention not based on existing technology?", then not only would the answer be "there isn't any", but as a corollary, one would have to conclude that there is NO example of ANY invention from ANYWHERE that isn't based on existing technology. Clearly that doesn't seem to be the intended reading of that question.

You can't make a Sprengel pump without distilling your mercury (it doesn't work if the mercury sticks to the walls of the tubes and leaves crap all over them), and you can't make a vacuum tube without some kind of hard vacuum pump, and, as I pointed out above, the Sprengel pump was the only kind of hard vacuum pump available for decades. (I already explained all of this fairly clearly in previous comments, such as https://news.ycombinator.com/item?id=28333304.) In fact, the invention of the Sprengel pump produced an explosion of inventions and discoveries, of which the so-called Edison effect was only one.

I do think that that there is no example of any invention from anywhere that isn't based on existing technology, including specifically existing technology invented on other continents, and my reading of the question was that it was intended to make precisely that point, thus concisely pointing out the ignorant fallacy at the heart of the original racist bullshit comment, "I can think of nothing unique, only modification of existing inventions."

Again,

1) the tools are traditionally not a part of the invention,

2) by referring to distillation as a prerequisite for the mercury vacuum pump operation, you're referring to a tool twice removed from the invention in question, and

3) even mercury distillation itself is not based on ayurveda anyway. It's based on physics.

I've commented further at https://news.ycombinator.com/item?id=28360306.