Pressure

Alex265

Brian, most of these pressuretrols are off

in the lower scale range, at least the 3 I have were all off. I did a 'live' adjustment (which I don't know if it can be recommended but it worked for me). With pressuretrol set to desired settings, I make the boiler run for a while so that pressure starts building up, and then I watch the pressure on the gauge and when it is close to the desired cut off, I start slowly turning the pressuretrol's adjusting screw (that adjusts cut-in) down until the pressuretrol trips. This always happened before the spring would go loose from the screw, which is also a possibility. Visually, during all this time the cut-in setting was on 0.5.

crash2009

According to

my brand new wika 0-3 psi, My system runs at .05 psi.  Assuming that there is 16 ounces in 1 psi and that .50 psi is 8 ounces this system is running at 8/10'ths of an ounce.  I just about filled the last rads on both mains this afternoon.  I think I will make that manometer that David and Jamie spoke of.  It will answer my question of what pressure am I running at.  Jamie answered it already when he said "an ounce or so" according to the gauge that's about right.  I guess I can't argue with the manometer.  Does the clear plastic tubing have to be a certain diameter? 

David Nadle

manometer

The tubing I.D. must match the size of the barb on the hose fitting. Seal the fitting with two hose clamps. clamp a hook to the open end to make hanging it high easy. If you want to get fancy, tape a yardstick to it.



Here's a pic of the one I rigged up.

brian_44

Yes...these pressuretrols ARE off...

..in a BIG BAD way. (At least MINE was).



Since I was so curious as to why my system was still running at over 5psi with the cutoff all the way to it's lowest point, I decided to take the whole thing apart. Pressuretrol, gauge and pigtail. (It needed to be cleaned out anyway.)



After I wiped the bottom of the pressuretrol, I BLEW into it...and was amazed at how hard I had to blow to hear the "click". I'm a bagpiper (so I am way full of hot air...maybe even more than a steam boiler! LOL) and I can tell you that it was WAY more that 5 PSI to hear that click.



Finally, I continued to adjust the screw and kept doing the unconventional "blow test" until it was fairly easy to hear the "click". The best I could get at is probably at about 1 to 2 psi without dislodging the screw from the spring inside the unit.



It's all put back together and I'll let y'all know how it goes! I have to laugh at the method myself, but if it works I'll be happy.

crash2009

I removed the screw completely

The pressuretrol I have will not shut off any lower than 3.1 psi.  I was thinking that if I put a washer in there, to essentially make the spring longer, maybe I could get it to shut off lower.  But I still would not get the accuracy needed to shut the burner after my last rad filled.



No offence Brian, but I think you maybe need to look into why your boiler gets to 5 psi, not nescesarily what it does once you get there.

brian_44

Thanks Crash

I'm not offended at all at your observation. I know for a fact the boiler is correctly sized, so I know that's not an issue. The only time the boiler gets near that level of pressure is when it's been running for a good 2 hours. I have excellent main venting and varivalve vents on almost all rads and everything heats fairly evenly. Once all rads are nice and hot, I noticed hissing from the upstairs radiator at which point I noticed the pressure when I checked my boiler.

I would guess that a boiler running for an extended period of time will continue to build pressure...



If you think I need to check anything, feel free to offer any advice. Other than that pressure situation. everything on my system seems to run great.

Rod

Calibrating Vaporstats/ Pressuretrols

Hi Guys- You might want to take a look at this thread on Pressuretrols. Gerry Gill invented a simple tester /calibrator for them which works great!

http://www.heatinghelp.com/forum-thread/128249/why-do-Honeywell-vaporstats-suck-so-badly

- Rod

crash2009

"How to trick#$%^ your pressuretrol"

Thanks for the link.

haaljo

The link to thread on ptrols...

was great, It reminded me of a thread that the pro's were talking about optimal start/stop for steam. Measuring the condensate return temp and delaying restart of boiler. I think the posters compared it to outside air temperature reset for hot water systems.

crash2009

2 hoffmans and only 3 clinks

I think I may have found a leak.  When it was suggested that I may have a leak, the first thing that came to mind was water.  I think my leak is through one of the main vents.  Specificly one of the Hoffmans.  I have been sitting in the boiler room observing how things are running, taking a few notes, etc. 

Once it starts steaming up into the mains, Main1 hoffman75 clinks loud and clear to let me know that steam has arrived.  Main2 hoffman75 has a quiet clink when the steam gets there, and a quiet clink after the cycle is over and the steam has left.  2 hoffmans and only 3 clinks. 

How do I test Main1 hoffman to find out if it stays closed after the steam hits it,  and could this be a reason why I only build 8/10ths of an ounce psi during a cycle?  I guess I could take it out and plug the hole, but I would rather do that after I prove its no good.  



Answered my own question...The Hoffmans were closing together and opening at different times.  Or vice versa. 

BobC

steam leak

Find a cold piece of metal and hold it above the suspect Hoffman,f it is leaking steam it should condense on the cold metal.



I should think it would have to be a substantial leak to not allow the boiler to build pressure assuming there is some excess capacity - which there sb on a mild day.



Bob

crash2009

That was quick

I just put a small piece of flat bar in the freezer.

jpf321

edr vs boiler size?

Crash --



What is your installed EDR and what is your boiler rated for? Low pressure does not immediately equate to leak. You system is constantly condensing and producing steam. You may be achieveing balanced steady state without building pressure. Pressure is only built when all rads are hot 100% (all vents are steam hot) and all pipes are being maintained at steam temp. AND system condensation is less than production.



If you can, try closing all rad valves and try to come to pressure. But be cautioned that a valve closed does not mean it will reopen gracefully.



Have you ever built over 5oz pressure? (since you have been steam smart?)

crash2009

EDR

EDR is 377, boiler is a eg55 with 510 sq ft stamped on the plate.  The other day I turned on the large exhaust fan in the kitchen for an hour and heated all the rads just about completely, a few of them were full, then the thermostat shut me down.  I can build pressure with the kings closed, real fast. 

I can close one of the kings and test each main individually.  Roasted tenant is much better on a colder day though. 

I have never seen 5 oz during a normal cycle.  on the 0-3 psi a normal cycle only pressures to .06 which is near 1 ounce.  

Yea, could be I'm just lucky, but I never win in Vegas. 

jpf321

instead of fanning kitchen

simply crank your stat up 10deg. you should be able to get to pressure on a 10deg increase in desired temp .. and it sure beats cooling your house for a test.



yes, it would probably be useful to close the mains individually .. at least you can then decide if 1 is leaky and the other is not .. heat up the entire system pretty well .. and then close one of them down .. you should get to pressure pretty quickly .. then open that one and close down the other ..



when was the last time your boiler soot was cleaned? perhaps you're not providing a good heat exchange surface because of soot. i assume that your burner has been serviced recently and that your stack temp is between 425-525defF GROSS?



normal system day, you should be able to make pressure in about an hour .. maybe 1.25hrs....definitely in 2hrs. this test can only be made by turning up your stat (t-stat or aqua-stat if equipped) .. or jumper TT at the boiler and let her run.

crash2009

burner, boiler soot and stack temp

I'll have to call Pat on that one and ask to what extent the boiler was serviced in June.  And I will have to wait for cooler weather to do more testing.  But thanks. 

haaljo

If one is not losing boiler water

then how can one have a leak? Crash will have plenty of opportunity to check pressure in the next couple of weeks according to weather.com.

10oz gauge just came and has been installed but it's 56 degrees here in Boston. Supposed to get down to the 20's on Saturday night. I don't know if I should wait or crank her up now. Gas is so cheap, I might pull the trigger tonight.

crash2009

Pat

our local steam guy said the burner was good back in June.  His guess, without looking, is drywall dust from the new ceiling.  He says that he thinks I am mechanicly inclined enough to take them out and clean them.  I guess I can visually inspect for soot at the same time. 

jpf321

take out...

take out what? clean what?



how does dust effect what? your vents? maybe.



yes check for soot at some point.

crash2009

Whoops

I can see where my last post would cause you to say WHAT?  Our local steam pro (named Pat) told me to take out the burners and clean them.  He said the burner was good when he left here in June of this year.  Since then I have put in a new drywall ceiling in the boiler room.  He suggested, that the burners have drywall dust in,on,around them and that may have something to do with my inability, so far, to build any pressure in the system.

crash2009

BobC

I tried that cold piece of metal idea.  I took the flatbar out of the freezer and put it up there beside the Hoffman.  I didn't see any steam condensing on the bar.  But I think the bar scared the Hoffman into working again.  I'll have to remember that trick. 

Hoff 1, anymore trouble from you and next time you get a smack instead of a tapp. 

Hey wheres that Haaljo 8 ounce gauge report?

haaljo

10 oz gauge report

Following up on no/little pressure discussion.

Boiler is 1938 National with EconoMite conversion burner. The boiler is rated at 150,000 BTU's. The burner says from 50K to 200K BTUs

Wika 10 oz gauge ($47 including shipping) from Industrial controls, cornelius, NC. ("Swiss Made")

Replaced 3# Wika gauge and turned on boiler today 11/20/10 at 0600.

Temp was 27F. Clear sky, light wind.

By 0800 making steam and could hear a lot of condensate returning (ear on pipe test)

By 1000 (four hours) 5 rads hot across and 2 convectors warm.

3 convectors cold as well as one radiator.

The gauge is just fluttering after 4 hours.

I go outside and clock the gas meter. HALF THERM/Hour!

Before the heating season, I had the boiler cleaned/adjusted.

It was an emergency because, I had MassSave energy audit done and the boiler failed the CO test. So, auditor had to call NSTAR gas and Tech came down. I was expecting the Tech to adjust as I have the yearly maintenance plan. The Tech would not deal with the problem. He said I needed a new boiler! He shut off the gas and red tagged it, I got a private Tech to come down the next day and clean the boiler and adjust the flame. But it was an emergency (no domestic hot water), it took over 2 hours to clean the boiler and did not pay attention to the firing rate. Have to give him a bye on that :-)

I called NSTAR about **** was that - denying service equipment.

NSTAR said they would give me a refund on my maint. contract.

So, Be aware - when you have an audit what could happen AND if you have a maint contract with NSTAR gas (boston area) you could be denied service.

(I have 2 CO detectors in my house one near boiler room - never had them go off - but I understand the importance of CO problem which has now been fixed).

Now, I have to call tech and get him to deal with increasing the firing rate although burning 50 cents/hour of natural gas is nice :-)

haaljo

10 oz gauge second report

Following up on thread on pressure and yesterday's first report.

I have had good results. Increased gas clocking from .5 to .9 therms/hour.

All radiation hot across.

New 10 oz gauge fluttering integrated over time at .1 oz.

I had rezeroed the gauge at .2 oz. Indicated at least .2 oz vacumn for about a minute. It pinned the bar so at least .2 oz

 Condensate continued for for 30 minutes by the ear test.

 1) I will rezero 10 oz gauge to 1 oz to see  vacumn.which is interesting for me because now I see the vapor vacumn theory of operation provided you can maintain a healthy vacumn for a long time. Hmmmmm?

2) Will now deal with the NSTAR gas denial of service. Haven't had my money returned since they refused to deal to honor their maintenance contract. That was their offer and I'll hold them to it or they give me another year free or something (I'm easy).  It's tough when your supplier is the only game in town but gas is so cheap]

3) Will follow through with the MassSave recommendations which aren't that many but when he took the CO reading it kind of put improvements to heating season on the back burner so to speak. But these guys know just about nothing on steam.

This thread has been very useful to me. Thanks

(OAT 35F, Sunny at 0800,  no wind. Beautiful day today in Boston)

crash2009

1 ounce

So, your new gauge is telling you that your operating pressure is 1 ounce.  I guess I am not far off when I said mine is 8/10ths of an ounce.  Jamie's statement was "about an ounce or so"  Was yours steaming for 4 hours straight, or just cycling on and off with the thermostat? 

check out this cycle 1 min on, 1 min off.  This is JPF's new Slantfin

http://www.heatinghelp.com/forum-thread/133034/duh-whoops-pressure-cycle-graph

haaljo

Pressure is more like a tenth of an ounce

as integrating the fluttering between zero and two tenths although I may be sersiouly off base. This is at .9 therms and it was a constant run for 4 hours as overode stat.

So, I have almost no pressure at boiler but pushing steam to radiators, plenty of condensate (ear test) and  oberved a vacumn at shut off which is because when I get a new system maybe I'll find a undead0man to see if vacumn vapor retro could be done. I can always go back to regular venting et al. A new heating system at $1/therm is getting harder to justify economically but tring to do a retro back to the Deadmen days would make it justifable (maybe not for my wife but it would help keep out of mischief. I have my arguments already to go).

I didn't know JP got a new system. I looked at the graph last night thinking it was his old clunker. He's no fun anymore? :-)

crash2009

1/10th

There's gotta be a blockage, doesn't there?  Does the pigtail get hot at least 1/2 way?  Have you pulled the pigtail out of the boiler and checked the tapping?  I found a piece of teflon plugging mine.  I could blow in but couldnt suck out.  The teflon was kinda pasted across the hole like a flapper.



JPF's Slanfin is  http://www.heatinghelp.com/forum-thread/132546/so-long-fitzy-hello-slantie  I really enjoyed the infared pics.  He always seems to find a new slant on things while on his quest to see whats going on inside the system.

haaljo

Pigtail is clear.

I am now seeing .two-tenth of oz. after tstat called for heat at ~1200 hours. Steady  one tenth with fluttering to three tenths so integrated = .two tenth oz. Stat satisfied in 30 minutes. OAT still cold at 36F. Sunny no wind,

I figure the pressure will increase if I increase therm/hour rate but waiting to see if I can get the vents to close with two tenths oz. at boiler. Jamie in one post on this thread said one may see the pressure increase dramitcally when vents close.

Didn't see much of a vacumn when boiler shut off at 1230.

Several pros have studied very low pressure operation. I believe Gerry Gill posted a rather elegant study including lamenting the lack of hi/lo burner's available for residential steam. Jamie has noted the ability to caputure waste heat from exhaust for steam boilers (but with consequences as to corrosion from condensate). Steamhead has discussed using optimization controls (Outside air reset) for steamers (which I still have trouble understanding).

It's just most of the engineers graduating in the last 20 years would rather see steam systems go away. They are taught the "inefficiency" of steam cannot be fixed and facilities should switch to hot water or scorched/chilled air systems.

brian_44

It worked!

It took a while because we haven't had any cold mornings until today...

Due to the inaccuracy of the pressuretrol on my system, I took it apart to adjust it. The reading on the front setting was NOTHING CLOSE to what the true cutout was, so I did the "blow test" noted above.



When the system is now running after a setback (in my case, bringing the temp up from 62 to 65 in the AM), the system cuts out at about 1.5 psi. That's way better than before..but still not to my liking. All of my radiators are hot and going nice well before pressure even registers on the pressure gauge. I'll probably pick up a vaporstat and low pressure gauge to have the cutout happen much lower than that, but at least it's not hitting near 5 PSI !

jpf321

the vacuum...

You see on your gaage exists only IN YOUR PIGTAIL. It's the only part not vented to the air. I stuck a needle valve on the end (see pics latest) to release that vacuum if I feel like it. I don't know if 1/4 NPT vac breakers exist...that's really what belongs there.



You may also notice a needle valve to isolate the v_stat for higher pressure blowdowns. Today I also installed my new snubber above that iso needle valve.

haaljo

10 oz gauge third report (11/22/10)

OAT 40F clear sky no wind

Increased gas clocking to 1.2 Therms/hour (previous night).

Boiler turned on by timeclock at 0530 after 10 hour shutdown

Went down to boler room at 0700 and gauge at firm Two (2) oz.(with  flutter).

Observed "large" increase in twenty (20) minutes to 8 oz with +/- 1 ounce flutter.

One of three #2 main vents hissing at 8 oz. (removed, now two #2's and four #1''s)

Turned boiler back on at 0850 after 30 minute shutdown.

0900 = 6 oz firm, 0905 = 10 oz firm with large flutter +/- 2oz.

Boiler shut down at 0905 and goes negative at 0906.

Bottomline

10 oz gauge (discoverd no pin at zero) indicates -3 (three) oz (not a vacumn gauge and jpf suggests vacumn is not indicative of boiler going into vacumn). Negative pressure greater than two (two) oz for two minutes, One main #1 vent sucking in air like crazy while system in vacumn. It's appurtenant to 10 oz gauge discussion but boiler water continues to make steam for longer (albeit very small) amount of time with vacumn. Here in Boston it's 212F boiling point while in Denver its 202F.

Bottomline

The 10 guage has helpful but now time to put back the 3 pound gauge and see if I'm going to have to get a vaporstat. Might damage the 10 oz gauge. Also, Don't know what the fluttering is all about. It was at a firm 10 oz but fluttering like crazy.

Now I can go and read more about JPF's new boiler postings :-) but late for work!

jpf321

snubber

i did obtain and install a snubber. it really helps eliminate the flutter/chatter.

http://www.gaugestore.com/prodinfo.asp?number=32618

crash2009

Cold snap along the east coast

spawns questions about pressure.

haaljo

Cold snap is over here in Boston

It was 24 degrees a couple of nights. I was pleased with my systems operation.

P'trol did it's thing a couple of times after night setback. The lowest I could set it was cut-in at 10 ounces and cut-out at 30 oz. Most of the time, the boiler ran 45 minutes and satisfied Tstat. Then off for 90 minutes. Then on for 45 minutes (with 1 oz in 15 minutes and 8 oz after addtl 30 minutes) then Tstat satisfied (66F).  Delta from 24F OAT of 42F and delta during the day about 30F.

There were beautiful sunny days with little wind. I look forward to seeing how the system operates on a design day in Feb. when it's 0 degress and the north wind is blowing (Not really). :-)

crash2009

Smells like polar bear out there!

We finally got some cold over here in Ann Arbor, Mi.   Smells like polar bear out there.  Nice and warm in here though.  Its supposed to go down to 17, maybe I will see some pressure tonight.  All the big rads are near full now.  This big Rococo has been doing 8 or 9 out of 11 all week.  We have been cycling off the thermostat so far this year.  Its about time the pressuretrol did some work.  I have been drinking my morning coffee in the boiler room all this week, and things seem to be running smoothly.  The Hoffmans have gotten their act together.  Gortons silently do their thing.  Gauge glass starts at 3.25" then drops .75" and runs at + or - 1/8 .  The water heater is louder than the boiler.  I think that one reason the operating pressure is so low (near 1 ounce) is just because there has not been enough demand for heat.  Maybe tonight...Dream on Crash! 

haaljo

crash - what rate is your gas consumption?

I'm clocking at about a therm/hour. Did see 24oz this weekend but that was on purpose. It's usually about an oz but could see 8 oz after night setback. Been a lot of degree days all over the country this winter. Even Europe. Part of climate change?

crash2009

I have no idea right now.

It is year end, and the accounting department is  busy wrapping up the year right now.  I usually dont review the year untill about January 15.  I do have all the data for 2009, just the $$, not the therms.  I plan to chart 2010 and overlay 2009 to compare. 

I am really happy with the piping upgrade.  I have not cycled on pressure 1 time.  The boiler just idles and the steam gently makes it way around the house.  I am sure we had some design days this December, it got down to 2 F, plus the 40 mph north wind.  I am beginning to understand that I dont need pressure to heat this place, just "full rads and a thermostat" you were right about not needing the vaporstat.  So far.  I keep hoping don't I?  Merry Xmas

crash2009

Here are the utility bill numbers from 2008 to now.

  I guess the bills are not too bad considering the place is 6000 square feet, has no insulation, and 100 year old single pane windows.  The only place that has insulation is the steam pipes 200 lineal feet covered with 1" fiberglass pipe wrap.  January and February have been historicly the most expensive to heat, time will tell how the repipe and insulation are doing, but so far it appears they are reducing the monthly costs a bit.  Last winter electric space heaters cost about $50 each/month, we don't need them anymore.

I did a rough measure the other day using the Mills 2-20-200 rule.  I guess Mr. Mills would have installed about 750 EDR in this place.  Currently we are using 375 EDR, 150 LF of mains, and about 50 LF of near boiler piping, to heat the place, connected to a 500 EDR Boiler. 

I did a little test the other day to see what would happen if half of the radiation was disconnected.  I closed the king on main 1.  Main 2 pressured up real good and fast, then something weird happened, The water got real low in the sight glass, so I shut it off just before going into LWCO and autofeed.

Then I closed the king on main 2.  Main 1 took some time to fill, about 12 minutes and then shut off on pressure about 5 minutes later.  I did not get the LWCO condition while testing main 1.  I wonder whats up with that?  I expected to get the same results. 

 

One side shut down on pressure, and the other would have shut down on low water if I had not shut down manualy .

Mark N

Are you sure

Crash



Are you sure you only have 375 sqft of EDR in a house of 6000sqft. My house is 1/5 the size of yours and I have 260sqft worth of rads. Are part of this house unheated and you are counting them.

crash2009

377 EDR

 Well it was a while back that I figured it out.  I may have miscalculated.  I can measure them again.  I doubt I will end up with 1000.    

Bear in mind though, that we have a developed walk-out basement, heated with the mains 75 LF of 1.5" and 75 LF of 2", and about 50 LF of various sizes in the boiler room.  Then there is all the pipe in the walls, another 200 LF.  Those have to count as something toward or against the EDR as well. 

The walk-out basement temperature is 65 F in the back half , and 72 F in the front.  There is not much heat loss down here.  I am practicly underground.  The foundation is "old style" carved rocks on the outside, then they mortared a layer of rock chips on the inside (its a couple feet thick).  The partitions down here are triple brick,  the letter "H" would best visualize how the bricks are laid.  Then, the brick chimney/fireplace....... Anyway the point is this old shack has some holding power.  Once you heat it up it takes a long time to cool off.  If the historical society would allow us to change the windows we could likely heat the place with light bulbs.  I think they are in ca-hoots with the gas company.

Mark N

Missing Rads

Are there pipes that are capped, no rads anymore. What is the size of the basement? Are you saying the pipes in the basement aren't insulated. I've seen somewhere how many btu's uninsulated pipes put out. By my calculations 377sqft EDR in a 6000sqft. home comes out to 15btus per sqft. Modern homes are like 30 btus per sqft. My house is 60btus per sqft. A 100 years ago they wouldn't have under heated a house.