In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
What is the procedure for sizing main vents in the basement for my steam system. I see a 35, 75 and 77 in the Vent-Rite non-vacuum vents. Each has a different operating P.S.I. I had a new furnace/boiler installed to replace the one from the 1960's and the installer never checked the system and it seems to function poorly. I have read about the need to balance and will be checking the individual radiator vent sizes. Possibly the mains are too small.
Thank you, Bob