coil/spring inside rad???

[ayesha]

Hi everyone, as i was dissconecting my radiator from the pipes (to clean and paint it)i discovered some kind of coil type spring about six-eight inches long coming out of the tap valve. (bottom end)it was quite easy to remove but ive never seen one of these in the past.Out of curiosity, whats it for?

 

[justlead1]

They are normally associated with micro bore system of C/heating where dual wheel head and lock shield valves were employed. or where one end of a radiator was used for both flow and return connections, designed so as when inserted the circulating water did not short circuit and passed through the whole of the panel area. Note some guys used copper pipe and as a result over time the electrolysis that take place between dissimilar metals corrodes the panel radiator.