You can try this translation service (I did it, crappy but better than nothing)
http://babelfish.altavista.com/babelfish/
For sealant you can use bathroom silicone, goop, loctite or other liquid gasket sealant you can find, no need to bond the layers permanently...
And yes, the thingie in the middle looks like a 'jet', but either too big for only one jet and too restrictive or too small and restrictive to be a full sized center inlet IMHO
Cheers and g'luck!