TWEAKING THE ONE PIPE STEAM SYSTEM QUESTIONS & OBSERVATIONS

ww

From page 7 of The Basics of Steam Heating

by Dan Holohan When the boiler is off, the "normal" water line is the center of the gauge glass. When the system is running, the "normal" water line is near the bottom of the gauge glass. That's because the water, in the form of steam and condensate, is out in the system. When the burner shuts down, the level will return to the center of the gauge glass again.



 My sight glass is in the middle. When the boiler is running and producing steam I see a little up and down movement but it doesn't have a water line at the bottom of the glass. Is this ok? I'd kind of figure when the water converts to steam there should be a lower level on the site glass. I've been tweaking the steam system lately.



 Tuned up oil burner, cleaned boiler. On the long mains I put one gorton #2 and one Gorton #1. The short main has a Hoffman 75 and one Gorton #1. I plan on making a pipe 18 inches back toward the boiler but looking for a fitting to angle it up slightly so water won't be trapped in pipe and vent.  May have to use a copper pipe or do some bending,etc..but it works ok but I'm just afraid of water hammer coming up from the return below. Any suggestions here welcome.



Also why did they use very little amount of vents when the system was put in and now I see vent setups with a dozen  gorton vents..i thought the dead men sized it all correctly or is there internal pipe corrosion buildup or something? I had some Hoffman 40's in all the radiators the switched some for Maid of the Mist C and D on the bigger radiators and checking how they work through trial and error.



 I've cleaned and adjusted the pressuretrol and am very observant of getting low steam pressure to bring heat up quicker to all radiators. As I read on this site I'm trying to vent out the main lines quickly and the radiators slower to get even heat. I read the article and saw the photos of the steam hogs and that was interesting.



 How much is the fee to go to these seminars and are there ever cancellations or room for one more after they are sold out? I'm fascinated by steam now.

ww

How I'll angle the pipe with vents

I'm going to use either a street elbow and or a combination of 90 degree elbows and nipples that are 3/4's and position the pipe just pitched above level so the water won't get trapped in the vents and so it will flow back into the return.

BobC

Why

A lot of the old systems were designed and installed when coal was king. With coal you started the boiler in October and pretty much kept it going through April in the northeast.  Steam was always being produced albeit very slowly when the coal fire was banked overnight. That meant the vents only got fully exercised if the fire was allowed to go out completely so there was no real need for rapid venting of the mains.



With oil and gas the boiler turns on and off many times a day and the vents have to clear out the air a dozen times a day so venting becomes more of a concern than it used to be when coal was king.



Bob

JamesC in Stamford CT

water line

I should think the amount of variation in the water level from a cold state to a steamy state would vary based on the size of the boiler and how big a system you have. I have a small (1,800 sf) house with only a dozen radiators and a newer (tiiny) boiler, and the water level changes very little. I think the book was just trying to explain the the mechanics behind why a water level may be observed to change during operation.

EBEBRATT-Ed

posts

I agree with the last two posts regarding venting and the boiler water line.

ChrisJ

Water line

Keep in mind different boilers require a different NWL.  For example many Burnhams call for the glass to be 3/4 full or so while Weil-Mclains call for 1/2.

My boiler is matched to the load and most of the time the water level doesn't drop at least not any noticeable amount.  However on a really cold night or during a recovery where the system runs for a long time it will drop quite a bit.  It all depends on how much of the boilers water is out in the system as steam.