Boiler mud leg

MEK

I have seen some advice in some of the posts on The Wall that recommend to "install a drain valve in the boiler's mud leg". I believe the purpose is to flush out sediment in the boiler.

I was trying to locate where this valve would be installed in the Peerless IOM for their series 63 steam boilers. I found an instruction to install a valve on the drain tapping, is this what the "mud leg" refers to? See attached image.

ChrisJ

My understanding is

the mud leg is the condensate return.  I am installing a short nipple with a tee and a valve on the end of the tee.

This picture shows the mud leg drain on my current boiler.  On the new installation I am using a 45 deg elbow to get the valve lower than the tee to allow it to drain better.

MEK

That makes more sense

If I understand you correctly, you are referring to the tee that comes directly out of the bottom of your boiler (as opposed to that pipe that comes in from the right, supported by the brick). It seems like when that valve is opened, it will drain from both the boiler and the return piping, but maybe that is the intent.

What is the recommended interval for flushing sediment? Yearly?

Thanks for your post and your picture, it was really helpful.

ChrisJ

Yes

You are correct.  The pipe coming across supported by bricks is the wet return which goes over to the hartford loop on the left.  When you open the valve in the mud leg it will drain the boiler and the condensate return which is a good thing.  If you have king valves installed as well as a valve in the return it will allow you to build pressure and blow the crud out of the boiler through this valve.



This video may be of interest to you.

http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping