Wstter hammering one pipe system steam heat

mob1345

We have had isdues in the riser pipe up on the 5th floor whete you hear real bad banging in the winter . Been asking the landlord for years to fix it . We were told the problem is most likely the basement nothing wS found up on our floor to cause this .so today plumber were here in the basement the open a wall on our section A . When we came home they threw this in the yard its pipingnthey cut out does anyone know what this is ? Is this where condensation is suppose to drip out

mattmia2

it is 3 pieces of pipe connected with a tee with a flange connection on it, possibly covered in asbestos. i'm not sure what the thing tee'd off of it other than it looks like it is plugged where it once connected to something.