Bobi:- When it comes to retrofitting radiators into an existing heating system, I would suggest that you get some local talent to help. All radiators are not the same. Some are designed for single pipe systems…some for other types of gravity piping…some for forced hot water…and some for steam. In the interest of doing the job right the first time, contact a reputable contractor in your area for some assistance. Lots of luck…Bud