Boiler Pipe Insulation

Rob Pickard

I have a couple of questions about insulating the near-boiler piping in my apartment building (see pictures).

First, do I want to put insulation on the base of the risers, right next to the boiler? The current insulation leaves a bare section of pipe on each of the risers.

Second, what is the device sticking off the pipe in the other picture, the one with the wheel on it? And would I want to insulate any part of that?

Thanks.

Weezbo

this is a one time only deal.

that is a rising stem.

completely sealing the insulation does the most for the steam delivery system to where you would like it to be.

Dave_4

Insulate

Weezbo is right- insulation of steam piping keeps things where you want them. To not insulate causes heat loss from the system and uncontrolled gain to the space around it. It can also cause banging.

The "rising stem" Weezbo referred to is an "OS&Y (Outside Screw and Yoke) Gate Valve". It would be your main isolation valve by the size of it. Exercise it once in a while to make sure it is working.

The reason for this style of valve is that when the valve is open, the stem is extended and when closed it is retracted, a quick visual indicator, not unlike the flagpole at Buckingham Palace.

On that valve, yes, insulate the body and at least the piping up to it.

There are professional commercial jackets which snap on and off. Those are not cheap and are more for personnel protection than actual heat loss. But the idea is to keep the valve bolts and body accessible for service too, something that packed-on cement would make difficult. Wrapping these odd devices in normal building insulation would be fine, just tape it neatly. The flanges can be insulated and covered with PVC covers made for the purpose.

While you are at it, insulate the return piping too. If you see bare pipe, go after it.