Mud leg drain

ChrisJ

I'm curious what are common ways to install a mud leg drain.  If the boiler has a 2" or 2.5" tapping for the return I assume you throw a Tee on there with a valve on the end.



My question is do people usually bush it down to 3/4" and use a typical boiler drain?  The way I see it I can either throw an ell on there to get the valve down below the T and bush it to 3/4", or install a full size ballvalve and adapt a way to hook a hose on it.  I assume a full 2 or 2.5" ball valve will allow a really good clean blow down as long as you use a large enough hose or is it simply not necessary?



I will be installing king valves as well as a valve on my return so I can perform the blowdown under pressure.

crash2009

This is how they did mine.

  Ell, reducer, drain valve. 



Pic also shows the Hartford valve.  When doing a pressurised back-flush, the Hartford valve must be closed, otherwise the pressure forces the water in the boiler up and over the Hartford.  I found out the hard way that this valve must remain open to run the boiler.  Cold house one morning, no water in boiler.  Thank god water feed was on the other side of the Hartford valve.



Way in the back there you can see some 1/2" copper...That line is the boiler water feed.  Most water feeds feed the boiler more directly than this one.  I do like it this way though.  The fresh water has more chance to warm up a bit before it gets to the boiler.  Most boiler feeds I have seen are installed on the other side of the Hartford.



If I had done more planning I would have done the return/hartford area a bit differently.  Perhaps closer to the design in the first pic.  Maybe next time.

Al Letellier_21

mdu leg drains

Neat way to do it Crash. I usually try to use an eccentric coupling or bushing but its a crying shame that too few supply houses carry much of anything now a days, let alone eccentric fittings. We did a Weil 5 section steamer the other day, had to use 5 different suppliers and waited two weeks to get the parts and fittings to make up the header....beginning to think a welder may be the cheaper and more time saving way out.......have two six section steamers sold and it will be 3-4 weeks before we can get the fiitings thru normal channels without having to ship them in and pay $$$ for freight....we steam guys get no respect, at least here in So. Maine.

Charlie from wmass

Al I feel your pain

I have had to use malleable fittings more as each year goes by. Do you have a F.W.Webb near you? They seem to have more fittings available on a more consistent basis.

Charlie from wmass

Feeding on the boiler side of the Hartford loop

is preferred because it allows for the water to be heated and deoxygenated sooner rather than hanging out and corroding the return piping. Unless there is a very good reason I will always put the feed on the boiler side of the loop for this reason.

ChrisJ

feed water

I have heard you should add water with the boiler running, is this true or false?



I know any added water must be boiled immediately but I am unclear on having the boiler firing while adding it. Seems like it would be difficult to determine the NWL with the system running.

crash2009

That makes sense Charlie

Like I said, we didn't plan that area much. Thanks for saving chris from the same error.

Charlie from wmass

Properly piped boilers

with fully functional returns and clean water so it is not foaming or bouncing add water while firing with out a problem. But the VXT water feeders have an adjustable delay so the water feeder takes a moment to think before adding water. This stops the burner and lets things settle for 2 to 10 minutes before slowly adding water.

ChrisJ

No feeder

I'm not planning on using an autofeeder on my new install. Even though I sort of like the looks of the VXT the fact is it will not even bother to add water unless the LWCO is tripped so it seems pointless to me. I am planning on installing a water meter though.



Honestly, I have no problem going down once or twice a week and looking things over, maybe adding a touch of water now and then. I feel its for the better.



I am curious, with the mudleg drain, would it be beneficial to add the T in between the return and boiler, with the valve facing straight down to act sort of like a sediment trap? Or would this be completely pointless?

Charlie from wmass

To answer your original question

I use blow down valves. They are like full port ball valves in 3/4" npt on the inlet and 3/4" hose thread with a cap for the outlet. I use a full size 90 or 45 with a bushing to 3/4" npt. Eccentric fittings are nice but sometimes hard to find. I find couplings are easier to find than bushings for eccentric fittings.

ChrisJ

boiler drain

When you blow down under pressure I assume if you pipe it right you can blow water out of virturally any section of pipe which you can isolate from the system such as your wet return assuming you install a drain on the oposit end as well as a valve to isolate the wet return from the steam main \ dry return.



However I'm curious, when cleaning the boiler it self is it better to blow down from the return section of pipe (the T entering the boiler with valve on end), or straight from the boiler drain?

crash2009

I blowdown from all three

  Primarily from the boiler drain (1) but also through the wet return (2) on the boiler side of the Hartford.  Also we installed a drain valve in the return tapping (3) on the opposite side of the boiler. 

Watch the video again?

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

Dam drywall dust!

crash2009

I just finished

draining a couple gallons from my boiler and return drains.  The water was kinda black on the return side of the Hartford which suggests to me that it was not de-oxygenated for a long enough time.  On the other hand, the water that came out of the boiler was pure.  This suggests to me that Charlie was 100% right when he said that the fresh water boiler feed should be installed on the boiler side of the Hartford.