hookah vs pipework

hookah

noun
  • A pipe with a long flexible tube that draws the smoke through water, traditionally used for smoking tobacco, which is often flavored. 

  • A tank-less surface air compressor pump and umbilical piping system that supplies air to a diving mask 

pipework

noun
  • Any system of pipes or tubes; piping 

  • The pipes and stops of an organ 

How often have the words hookah and pipework occurred in a corpus of books? (source: Google Ngram Viewer )