Welcome! Here are some tips for using this forum.
10 PSI versus Maid-O'-Mist
I'm considering a high-pressure blowdown this spring of the 52-year-old Weil McLain E-9 that came with the house. Idea is to clean out much of the junk accumulated at the bottom of the vessel. Is certain it has never been done before.
I would prefer to flush it out with a wand, but along with several other errors whoever installed it ran the Hartford loop piping directly in front of the skim port. So unless I want to dismantle this piping (which I don't), wand cleaning through the skim-port appears improbable.
In addition the boiler has been successfully cleaned with TSP and is running with 80 ppm phosphate from TSP-as-an-additive, has very clean water and dry steam, and so I have no compelling reason to risk problems by opening the ancient skim-port-plug.
The same said installers of course did not install a king-valve.
I haven't been able to find maximum pressure information for Maid-O'-Mist Jacobus vents, so I'm wondering if anyone can comment on whether the assortment of new Jacobus vents are likely to be damaged by the 10 PSI generally suggested for high-pressure cleaning blowdowns.
Perhaps worth mentioning that the system was running at 4 psi every cycle with the old Pressuretrol set for 2-in 4-out when I first arrived. However the new vents were not installed until after the pressure was reduced.
Also have one each of a Gorton #2 and Hoffman 75 main vent, and one Gorton #4 radiator vent installed. And a Matco-Norca AVA-125 that I would enjoy putting out of it's misery.
I suppose I could close all the radiator valves.
Another idea is to take a risk and remove the entire cover plate that hosts the skim-port and then clean with a wand. This might not be so risky as it sounds because all the bolts have been replaced recently. Probably the gasket failed and it started leaking so it was necessary maintenance. Touching it again seems far less scary than if the bolts were original--but I could be wrong about that. No experience in this area.