Boiler Blow Down: American Style

I’ve never seen or heard about a boiler with a single bottom blow down valve. I’m not saying they’re not out there, but they aren’t teaching that set-up to us.

To make sure the O/B pipes have cooled do you just touch them and say, yeah, cool enough? I wasn’t taught to do that, either. I was taught to shut the boiler’s distal blow-down valve, then the proximal valve, then run down to the tanktop and shut the O/B valve straight away. Thinking about your point, though, maybe a closed and cooling O/B line would pull on the distal blow-down valve and O/B valve and eventually cause them to leak or stick. Possible? How cool should the pipe feel before the O/B valve is closed? Should a thermometer be fitted?

Yup, that is it. There is a commercial name for the, but I tell you, it has been so long, I have forgotten. In our case, the spring was completely corroded. . .we split the cover and found nothing but rust. Easy to replace with new, anyway.