Remnants from an old Safety Vapor sytem.

The radiator vent being used as a main was first on the agenda. When the owner said 2 of the radiators that used to work, no longer work my guess was that radiator vent is no longer doing anything. BTW, that's the only vent on the whole system he could show me. There are 2 mains that end at loop seals and no main venting. That's why I was surprised 2 radiators were his only issue.

Haven't had a chance to get over there yet. They sent a few more pictures. We've all seen worse but they aren't great. Hoping to get over there this coming week.

@AMservices Here's a pic from another angle. Behind the gauge glass the letters OZ.

The system was not full of steam. The video doesn't show the gauge glass at it's worse. It bounces much more violently and foam fills the gauge glass above the water line. The water line in the gauge glass on the boiler goes all the way to the top and stays there until the burner shuts down. Looks like a tilting water line to me. I didn't want to put one of my vents on there with all that going on. I'll go back, remove the 2-1/2" plug on the RH side, install a 2-1/2"×1-1/2" bushing & nipple, skim and wand wash the boiler. Once I have it calmed down I'll install a Gorton 2. I'm adding up the EDR now but my guess is the boiler is grossly oversized. The installer actually told them he gave them a larger boiler than the one he bid. He let them know the larger boiler costs more and asked them to pay the difference. They told him no way.

Dunkirk/Bryant PSB-7D 225,000btu 571sqft steam
Total installed radiation 492sqft. Oversized by roughly 20%

@Steamhead There was someone else who posted about a Safety Vapor system he had in his home. I think the name was Silkey?

Slowly ironing it out. After skimming and wand washing the boiler, i replaced the Hoffman 40 being used for a main vent with a Gorton 2. The pigtail and gauge glass valves and piping were plugged with sludge. For now the boiler is no longer surging and foaming. The system will still need some work but for now there's no more hammering and they're getting heat in radiators that never heated well at all. I guess they will be able to ditch the electric heaters they were using for those rooms.
Some time in the 50s, someone put convectors in the livingroom and kitchen. One of the convectors in the livingroom had a 1/2" radiator valve on the return side, the other one has a Safety Vapor return valve. I installed a Hoffman 17C on the convector that had the radiator valve on the return side to prevent the steam from filling the dry return with steam and shutting off my new Gorton 2. That worked fine. After running the system another cycle, the Safety Vapor valve let steam pass into the dry return and again close the new Gorton 2. I guess I can safely assume the Safety Vapor Return valve from 1915 is not going to work on a 1950s convector.

https://youtu.be/z6NY6uHKz_M