No Pressure?

Rob_40

I have an old single pipe steam system with an coal furnace converted to gas.   No equalizer, no Hartford Loop.  I get heat.  I keep the water line 24 inches below the 90 degree bend in the single steam riser.   While waiting for the JD Weld to cure on a leak in the skim port nipple, I began to wonder why the pressure gauge never moved off of zero.  I wondered if the gauge or the piping that serves the gauge and pressuretrol were crudded up.   I took off the the gauge and the gauge responded to me blowing into it.  The pipes were clear.  The port for the gauges was clear.  (I could easily blow into the boiler steam chest.)  So if everything is working, why is there never a reading on the gauge?  I check the gauge when I see the inspection glass water line go up and down from the boiling.   I check the gauge when the radiators are all hot.  Is it possible that I don't need any pressure to heat my home?



Rob

RonNY

I think that's a good thing...

There's actually another thread going on this topic right now (http://www.heatinghelp.com/forum-thread/138281/Pressure-vs-Load). I'm fairly new at this, but if my reading of that thread is correct, then no pressure is good pressure.



When your boiler makes steam, it needs to displace the air in your mains and radiators. The air is pushed out through vents by the force of the steam, until there is no air left and all of the vents have closed. Continuing to make more steam past this point is unnecessary and wasteful.



The other possibility is that you're producing steam faster than you're venting air, and the steam is hitting resistance rather than filling your pipes and radiators. The pressure builds up because the steam can't reach its intended target. This is also not a good situation.



If you're producing enough steam to heat your home such that the thermostat turns off the boiler before you pressurize the system, then you're simply not wasting energy by generating excess steam. I think I'm in the same boat, as I've never seen my pressure needle move. Of course, the installer put in a pressure gauge with a range of 0-30 PSI with a cut-off at 1.5 PSI, so I guess it's possible the needle just isn't sensitive enough to register. :-)



Looking forward to this getting either confirmed or shot down, as it's an interesting question...

crash2009

Yea, It's possible

that you don't need pressure to heat your home.  Another possability is that the gauge you are looking at is a 0-30 psi which is unable to display the low pressure you have.  Many of us have installed aditional gauges to see what those low pressures really are.  A while back I added a 0-3 psi so that I could see where I was at.  I was surprised to see that sometimes my pressure was .05,  yes, fractions of an ounce.  0-3 psi gauges are available at http://www.gaugestore.com/  Wika is the usual brand.  You will need to install a T in your setup for the new gauge.

MrDvorak

Likely just low pressure

Most of the time, my home gets heated with pressure under 0.1 PSI. A 3PSI gauge can register that pressure, a 30PSI gauge can not. If you let your boiler run for a long enough time (half of an hour, an hour, several hours...), pressure will eventually show up on your old gauge if it works - the energy has to go somewhere, unless you have a bad steam leak somewhere, of course.