What is this?

icy78

Sadly, I've been out of the residential boiler scene for a few years now, but had an afterhours call this weekend which we put off till Monday. I asked the customer to send a couple pics as the system description sounded pretty old.

In a pic i see what I'm guessing to be a draft hood, about ½ way along horizontal flue section. If so, is that a installation that was typical "back in the day" or... ?

I see in another Pic that the relief valve is plumbed directly to th

e PRV which I'm sure is wrong, at least by code and maybe common sense:).?

Anyhow, looking for you guys knowledge/commentary on those 2 pics.

Thanks!

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mattmia2

Relief valve is ok if there is no valve between it and the boiler.

the draft hood in the vent is usually done with a conversion of an oil or coal appliance to gas that did not have a draft hood. I think a draft regulator is a better way to do it.

hot_rod

There should be a backflow device before the fill valve.

icy78

https://forum.heatinghelp.com/discussion/comment/1841641#Comment_1841641

Ok thanks for that info.

Meanwhile, I found what i think is the correct mechanical code for this situation and I read that as saying this install is incorrect as there is a PR valve next to it. Yes?

Also for more discussion, if a relief can be located anywhere on a pipe attached to the boiler…, what would be the limiting length of the pipe the relief is located in? It seems I always see reliefs within 4" of a boiler. Wouldnt a long pipe run lower the capacity of the relief valve?

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mattmia2

"valves shall not be installed" means there can't be a valve between the boiler and the relief valve or in the discharge of the relief valve so you can't isolate the relief valve from the boiler or close off the discharge. the relief valve with the tee built in and the prv connected to it isn't what this rule is referring to.