This is a model BETE TF56FC   012   with a male NPT 1 1/2" thread.

The image is of a BETE spiral deluge nozzle - one use is to protect in the event of a hydrogen flouride accidental realease.

This unique nozzle design, patented by Bete, an English company,   has several very cool advantages.   1.   the droplet size of the exiting fluid is smaller than all other nozzle designs.  (advantage is - if you are trying to absorb/wash down a gas in the atmosphere, the smaller micron size of the exiting fluid the more contact there will be with the gas).  2.   The nozzle has no throat restriction - so if there is rust or other contamination in the pipeline, the nozzle will not be apt to be clogged. Also, the nozzle can discharge a slurry, or a fluid containing lumps.   

Here is a BETE chart re: droplet size created by different types of nozzles.

A few hours ago I knew very little about this visually different nozzle, but with the internet, and a bit of perserverance, I finially hit on the manufacturer.  

What do you know about nozzles?