Pipe insulation

Jack Demczuk

Thanks for the info.

Jack Demczuk

pipe insulation

My house must have had asbestos at one time because none of the pipes have insulation on them and I read here that they are supposed to. Anyway, someone told me just to insulate the mains and I don't have to worry about doing the returns. is this correct? What is the benefit of insulating the returns it they are just carrying spent steam or water? Thanks for your info.
-Jack

GusHerb

insulation

if you have two pipe steam its good to keep the return uninsulated . with hot water you insulate the return.

Brad White_34

Insulate All

Insulate the mains and returns. Mains generally require 2 inch thickness for steam piping over 1-1/2" IPS and 1.5 inch thickness below that. This should cover all steam piping in a residential application, the 2 inch thickness applies to pipe up to 4 inches.

Remember, we are talking moulded fiberglass here, NOT foam, which will melt at steam temperatures. There is a high temperature foam (300 degrees) by Armacell (the Armaflex people) but I know nothing in detail about it.

Returns can get away with one inch but please do it. Corrosion will result if it has not already due to absorption of CO2 and formation of carbonic acid.

Best bang for the buck is in insulating straight runs. Fittings are fussy but worth doing if you have the time. As I have said here before in other responses, "insulating is an easy job to do, but a hard job to do well". A professional job looks it.