I am currently installing a hot water exchanger to my wood boiler and and a bit lost when it calls for a baseboard tee to be installed at top of the exchanger just what is this part. A way of releasing air in system. can I replace it with a standard valve? Help been to a couple hardware stores and they have never heard of this part.
This part may be known locally in the Northeastern U.S. by that name. Technically, as it is used commonly with 3/4-inch copper tubing, installers might also ask for a 3/4 by 1/8 FPT by 3/4 solder tee; although they come in larger and smaller sizes for other tubing sizes.
A baseboard tee looks like a brass or forged copper solder elbow with a 1/8-inch female pipe tap at the curve. Air vents or plugs are screwed into the tapping to permit air removal or gauge service at a later date.
Go to http://www.hydronic.net in the series design course there to see the proper use of the tapping and fittings that insert into them.