Maid-O-Mist Steam Vent 1/2 " Fpt, 3/4 " Mpt Straight

This is a main-line steam vent valve. I used it in a one-pipe steam heating system in my home, and it works just fine. It has a large air orifice and threads: 3/4 inch male, 1/2 inch female.

Works fine it is very noisy, a lot of knocking and steam noise... Impossible to sleep if it is in a bedroom

If you need a quick fix to your main vents then this is ok.That being said I already have an issue with one of them spitting steam out and not closing properly. They have been installed for 3 weeks now.

Perfect fit.

This is for a furnace vent, not your radiator. Works great for the furnace.

This vent was intended to replace an old corroded vertical discharge vent that failed and discharged water. This vent threaded easily onto a cast iron pipe from mid 1960's without any issues. The air is discharged at a greater speed than older mainline vents and produces minimal noise. i noticed that the radiators became hot in a shorter period of time in my 3 floor household.