2 pipe air venting

mikedo

does anyone know how this works I'm assuming it also vented the air from the old 2 pipe steam system

mikedo

found an old post and its all explained on page 237 lost art of steam heating. all the old return traps and air elimination parts were on the ground.

Mike_Sheppard

That is a Dunham return trap. There’s a float in there. Once it fills with enough condensate, the float rises and allows steam to enter from the boiler, which gives the condensate enough of a push for it to be able to get back into the boiler.

Dan’s book, The Lost Art of Steam Heating, has a great description of these.

Attached are some pictures from the book that might help.