Small steam leak at shut off

Unknown

Hello everyone.



I have a one pipe steam system from late 1800's with large wrought iron tubular radiators (really cool). I had a new boiler put in last winter and have been chasing steam leaks all over the house. I just stumbled upon a small one on one of my shut off valves at the seam on the top of the ball. I have pointed to the location in the attached picture (for some reason the picture is rotated. It is not really on the wall). Can I just turn the nut at top or can it be patched in some way?



Because of how old my system is, I don't like to turn a wrench unless I know it is ok to do so.



Thanks Craig

BobC

Pressure

You state that you have been finding leaks all over the place. If the system didn't leak before this might indicate the pressure is too high.



What pressure is the pressuretrol set to. The pressuretrol is a small grey box that senses the pressure inside the boiler. The common type should have the tab on front set to 0.5 and the white wheel inside should be set to 1.



Take some pictures of the front of the boiler that shows the pressuretrol and the sight glass and take one that shows the whole boiler and the piping around it 9stand back so we see how it's all set up).



Are you sure the water isn't coming out of the valve stem and then dripping down to that seam? When you try and tighten that valve don't go overboard with the wrench.



Bob

nicholas bonham-carter

steam leaks after new boiler installation

there are 2 joints there on that valve, the packing nut, under the valve handle, and the bonnet under that. use a flash light when it's dark and you will see where the steam is leaking.

the packing nut can be tightened up, and so can the bonnet. bonnets rarely leak unless really loose, or the pressure is two high.

i suspect the pressure is now much higher in the new boiler than in the old. unfortunately, the supplied 0-30 psi gauge is useless for this type of diagnostic work, so plan on getting a 0-3 psi [gaugestore.com] and put it on the same pigtail as the pressuretrol.--nbc

Unknown

Boiler

I replaced my boiler when I bought the house and never noticed these leaks last winter. It's been a colder winter so my boiler has been running a lot more. Most of my leaks are at the valve stem and I have one small leak at a union between the radiator and shut off that I am waiting until spring to fix. This one is definitely at the bonnet. Little bubbles can be seen.



Pictures below.



I never see the dial gage move much at all. The water in the sight glass is always about 1/2 way or higher. I usually have to add water every 2-3 weeks. It looks like the pressuretrol is set around 2 to 2.5 PSI? Is it normally lower?

BobC

Piping and pressure

It looks like the installer used a reducer on the boilers steam output port, that is not good. The piping should be at least full size from the steam output through the header and up to the steam main. If it's not you may well be getting wet steam that reduces the systems efficiency. take a look at the install manuals piping diagram and you'll see they are VERY specific on the size of pipe that should be used.



That pressure is too high. Turn the screw on top of the pressuretrol to set that tab down to 0.5PSI and ten take off the front cover and adjust the wheel to 1. That should let the boiler cycle between 0.5 and 1.5PSI whil;e it's steaming. the 0-30 gauge isn't much good at that low a pressure. A lot of people add an auxiliary 0-3PSI gauge so they can see exactly whats going on.



I see a lot of rust in the lower part of your sight glass, is that just on the inside of the glass? Is the water in the glass bouncing around a lot when the boiler is steaming?



Also all the steam piping should have a minimum of 1" pipe insulation on it.



Bob

Unknown

Thanks.

I'll get the pressuretrol bumped down. I never noticed the reducer. I know the the installer didn't want to touch much of the existing piping because it is al asbestos wrapped. Maybe that is why he went with a reducer? I am looking to get it removed or encapsulated properly.



The rust is on the inside of the sight glass. The water level does bounce up and down is that normal? I am due for a cleaning and will see if I can get the system flushed.

Unknown

Question on the wheel

What does the wheel do?



Also you guys have been great. Thanks for all the help.