Air compressor drain valve weird spiral attached

[GSinILL]

I am overhauling an old horizontal air compressor.
It has a drain valve in the middle of the tank on the side.
When I removed it, I found out that it has some weird steel spiral attached to it.
Any idea what this is for?
Picture attached.

Thanks
GS

 

[The Cobbler]

that's a dip tube. supposed to goe to the bottom of the tank to drain the water