That pigtail looks to be a nozzle for the end of a water line. We use these where I work in one of the vessels when it goes through a wash cycle every 36 hours. You can also see them on fire sprinkler systems.
"Beer is proof that God loves us and wants us to be happy"
"Imagination is more important than knowledge"
"Stupid is as stupid does"
"Everyone has a plan-until they get punched in the face"