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Joined on November 14, 2009

Last Post on August 3, 2014

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Getting steam to the mains

@ January 23, 2010 6:45 PM in Getting steam to the mains

On my system (see stats in my signature line), it takes 3 minutes on average for steam to move through 3.5 feet of 2-1/2" pipe between the last boiler riser and the mains.

Once the steam is in the mains, I'm seeing pretty good open-pipe times of 2:00 for a 26 foot run and 2:30 for a 44' run, both 2-1/2" pipes, which works out to 13 and 17.6 ft/min respectively.

So one ft/min in the boiler header seems awfully slow. Is this normal? Can anything be done to speed this up?

Would this work?

@ January 18, 2010 10:38 AM in adding a high water cut-off?

What if you installed a probe-type LWCO somewhere in the top of the boiler header piping. Wire it to the autofeeder so that it opens the circuit when it detects water (normally closed circuit, opposite of how it works in the boiler). If your autofeeder goes berserk, this should cut it off when the boiler header floods, but before water gets into the mains or rads.

My CycleGard LWCO can be wired for normally closed or normally open operation, so that part can be done. Not sure if the probe would be damaged by long-term exposure to steam.

Just a thought.


I have a HydroLevel CycleGuard...

@ January 6, 2010 11:18 AM in LWCO: float vs. probe .. pros & cons?

probe-type LWCO on my new Utica boiler. It operates just as you describe. Just when the system gets good and hot, the LWCO goes into "intermittent level test" (ILT) mode, shuts the burner off for a minute, and then restarts. CycleGuard models ending in 1090 do a 90 second ILT every 10 minutes, those ending in 2060 (like mine) do a 60 second ILT every 20 minutes.

Like jpf321, I've ordered a few of the Lascar USB data loggers. When they arrive, I'll see if I can determine the effect of the ILT on the system. I've ordered a couple of thermocouple models, an ambient, and a 4-20 ma logger that I'll be plugging a 0-3 psi low pressure transducer into. I'll post here if I get any results worth mentioning.


When making main vent "antlers"...

@ January 5, 2010 5:02 PM in When making main vent "antlers"...

... for Gorton #1 and #2 valves, does it matter whether the #2 vent is located at the far end of the antler or closer to the main?


Usage tracking on new thermostats?

@ January 2, 2010 11:42 AM in Usage tracking on new thermostats?

I have an Honeywell CT3600 7-day programmable thermostat that I installed on an oil-fired one-pipe steam system when we bought the house in 1998.

This thermostat has a nice feature that tracks the time that the thermostat calls for heating or cooling. It gives you the time elapsed today, the total for yesterday, and the total since the usage timer was last reset.

I use this feature to track fuel usage, resetting the timer at each fuel delivery, and calculate a bunch of averages including thermostat hours-per-day, gals per day, boiler firing rate, and cost-per-day. I also predict the next fuel delivery date.

Do the new Honeywell VisionPro thermostats have this usage tracking feature? I didn't see one in the user's manual. If not, can anyone recommend a 7-day programmable thermostat that does have this feature?


More for analysis than control

@ December 29, 2009 9:51 AM in Data acquisition on residential steamer

Hi Rod,

That Siemens box is too rich for my wallet, and proprietary to boot. I was looking for something more along the lines of hobbyist or low-end commercial discrete and analog data acq I/O that can be interfaced to a PC running SCADA software. The X10 home control stuff doesn't have what I need, but the industrial grade Siemens stuff is a bit too far in the other direction. The tekmar looks interesting, but still a little pricey. I might consider it if I was convinced in would pay for itself vs the controls I have now.

What I'm really looking for is to collect enough data to spot trends that indicate maintenance or performance issues that you might not notice on a day-to-day basis. A gradual increase in average pressure over time could indicate venting issues, for instance. Changes in the duration or frequency of thermostat on-time versus burner on-time, LWCO activity (mine does an intermittent level check in addition to the lwco) , automatic water feeder activation could identify other issues.

I wasn't planning in trying to do too much control, maybe a Vaporstat-in-a-PC algorithm (still on-off, not modulating), and temperature control on the domestic hot water mix valve (the proportioning valves I've tried don't work when the boiler is running and the hot water temp is 190 degrees). Either one would be expensive. A 0-5V low-pressure transmitter is around $200 (discrete outputs are relatively cheap, though). To do the temperature control properly I would need a flow meter, temperature transmitter, and an electrically operated modulating valve to control the cold water inflow based on the downstream temperature's deviation from setpoint. Here too, I can do the P+I algorithm in the PC, but the physical hardware is costly.

This is a little too much like my day job (I engineer control system software for industrial batch process applications), maybe I should get another hobby. :-)


Sometimes conjecture is all you have to go on...

@ December 27, 2009 8:34 PM in Venting question

>> I think that you should treat each vented segment as it's own "row" in the spreadsheet.

That's where I'm at right now with the spreadsheet.

Let's take the 12'/39' segments for example. The 12' segment ("A") is 2-1/2" pipe and 0.360 cu ft, and the 39' segment ("B") is 2" pipe and 0.897 cu ft.

According to the spreadsheet, in order to vent in 1 min with 2 oz pressure, I need one Gorton #1 on segment "A" and two on "B". But with these vents, won't it actually take 2 minutes to vent all the way to "B"? Seems to me that if it takes a minute to push the air out of the "A" segment, we haven't started on the "B" segment yet, so the times are additive.

So if I plug the "A" vent and figure the venting for the sum of the two segments, I get three Gorton #1's at the end of the main. And the math tells me that this arrangement should vent in 1 minute. So maybe the real estate guys were right, it's "location location location".

And yet, I keep coming back to why the Dead Men put that first vent there to begin with. In the physical arrangement that junction is a 4-way intersection - the main makes a 90 degree turn to the left, then there's the vent, and there's a condensate line that drains the 39 foot segment. From everything I've read it shouldn't matter, but somebody thought it did once upon a time.

Maybe the only thing left to do is to experiment. An extra Gorton #1 or two,and fittings isn't exactly going to break the bank, after all.


Venting question

@ December 27, 2009 2:45 PM in Venting question

I have a one-pipe steam system with a new boiler, and have been working through the venting calculations using the Gill/Pajek tables and the spreadsheet from JP Freeley. Based on the results, I'm planning to replace most if not all of the vents on the mains and radiators. As someone said, a new boiler deserves new vents.

I've attached a diagram showing a simplified version of the main layout (the real thing is more convoluted piping-wise), showing the relative locations of the vents, condenstate returns, runouts, the total connected radiation at each runout, and segment lengths. It's basically a big "H" pattern with the steam entering the main in the middle. The left and right runs on the bottom each have a vent at the end, no problems there. But the runs on top each have a vent in the middle of the run in addition to the one at the end. One run has the condensate return at the end of the run, the other has the return just after the first vent. How do I calculate the venting for the runs with two vents in a row? If [A-B] is the run from the main to the first vent, and [ B-C] is the run from the first vent to the second, then

1. Is the first vent volume = [AB] or [AB]+[BC]
2. Is the second vent volume = [BC] or [AB]+[BC]

Or is it something else entirely? I want to get this as correct as possible before I go buying vents for 6 main spots and 14 radiators, plus one spare of each kind.


It's a controls geek thing

@ December 21, 2009 3:26 PM in Data acquisition on residential steamer

Hi David,

Thanks for the feedback. I really haven't set a budget, I'm still in the investigation stage trying to figure out what the parts are going to cost me. This is more of a geek project as opposed to something I'd expect to get a return on investment (though if that happens I'm not complaining!) I have a spare PC (a laptop) that I can dedicate to this, and there are several free or low-cost SCADA programs out there. But they're no good without I/O and transmitters.

$200 for a low pressure transmitter doesn't sound too bad if you take into consideration what a vaporstat costs. I've read the threads on the poor quality of new vaporstats, and it seems to me that if I can get good readings off of a PT, there's no reason I couldn't create my own vaporstat algorithm in the PC and have it drive a DO to control the burner. Of course, I'd have to leave the pressuretrol on to keep to code.

You've pretty much nailed in concept what I'd be looking to do with trending the various burner controls (or perhaps more accurately, the burner control interruptions). Yes, it's all 120V, though I haven't dug thru the wiring yet.


Data acquisition on residential steamer

@ December 20, 2009 5:51 PM in Data acquisition on residential steamer

I'm a homeowner with a near-100 year old one-pipe steam system, and great appreciation for the knowledge contained in Dan's "Lost Art" book. A couple weeks ago I had the boiler replaced with a Utica Starfire SFE5175, with a Beckett AVG burner, Hydrolevel LWCO and feedwater controls, Honeywell PA404 pressuretrol and L4004 aquastat.

I was wondering if anyone has set up PC-based data acquisition instrumentation on a residential boiler to record and trend key operating parameters. I'm interested in collecting the following data (for starters):

- Boiler pressure
- Thermostat "call for heat" on/off time
- Burner on/off time
- Domestic hot water temperature

If anyone has done this sort of thing, I'd be interested to hear what you used for transmitters, data acq i/o, and PC software.


"Lost Art" saves the day

@ December 11, 2009 12:16 PM in New installation, odd old Hartford loop

Installation's done. Here's the story of a "near miss".

The good news is that the Hartford loop was stripped back to the returns and re-piped, and it looks a lot like the pic Rod posted of Clammy's installation.

And then the fun began...

So I go downstairs to check on progress, and I find the two boiler risers are only 18" above the water line instead of 24" like they're supposed to be. And the takeoff for the main was in between the risers, a perfect example of the "Never Do This" diagram on page 51 of "Lost Art". Why? Because "this is how we always do it and we've never had a problem". Sure. After some, ahem, discussion they agreed to re-do the near boiler piping in accordance with the manufacturer's spec.

So all's well that ends well. The boiler is running well. No hissing or spurting vents. No water hammer. No surging. Radiator sections that haven't seen steam in at least 10 years are heating up.

Thanks for the help guys.


Answers for Slim

@ December 8, 2009 12:30 PM in New installation, odd old Hartford loop

Hi Slim,

1. No, just a cleanout port. Why it's there is question for the long-gone guy who installed it.
2. We'll find out once they've got the new unit in place. If not, they're adjusting it accordingly.
3. No. I think I'm the only one in the house who's read "Lost Art". That's why I'm here to keep an eye on things.


New installation, odd old Hartford loop

@ December 8, 2009 11:26 AM in New installation, odd old Hartford loop

I'm having a new steam boiler installed today. They've just removed the old unit. The new one is a Utica SFE 5175S.

There's a somewhat unusual Hartford loop configuration (see photo). Condensate return lines come in from the left and right. the left one is at the base of the old boiler, and the right one is about halfway to the water line. The steam mains are 45" above the water line.

So, a few questions:

1. Is there any need to change the Hartford loop configuration? The installers are puzzled by the Harford vertical pipe coming out of the upper condensate return, but I question whether it matters as long as the returns are connected to each other (which they are).

2. Is there any point in elevating the new boiler to near the level of the higher return line? Wouldn't this effectively make a "buried" wet return of the lower one? And I'm not too keen on the idea of eating into the space between the water line and the mains.



@ November 20, 2009 5:03 AM in Boiler sizing: A little under, a little over, a bit more over?

Oil fired. The makes & models are:

(A) Utica SFE-4150S, 533 sq ft EDR (12% under calculated load), AFUE 81%
(B) New Yorker CLS-5, 592 sq ft EDR (3% under), AFUE 81.2%
(C) Burnham MST-629, 629 sq ft EDR (4% over), AFUE 86%
(D) Utica SFE-5175S, 633 sq ft EDR (5% over), AFUE 83%
(E) New Yorker CLS-6, 683 sq ft EDR (13% over), AFUE 81.5


Boiler sizing: A little under, a little over, a bit more over?

@ November 19, 2009 8:08 PM in Boiler sizing: A little under, a little over, a bit more over?

I have a one-pipe steam system in need of a new boiler. The connected radiation is 605 sq ft EDR, by my calculations (thanks Rod for the radiator sizing info!). If I've done the math correctly, that's a net ~145 MBH.

Boiler "A" is net 128 MBH, 12% undersized.
Boiler "B" is net 141 MBH, 3% undersized.
Boiler "C" is net 149 MBH, 3% over.
Boiler "D" is net 153 MBH, 5% over.
Boiler "E" is net 163 MBH, 12% over.

My inclination is to go with either "C" or "D", under the presumption that more is better, but not a lot more. Am I on the right track?

Boiler "C" is also rated 3% more efficient than "D" (86% vs 83%). Is a more efficient unit that is closer to the calculated load should be better than a less efficient unit with a higher rated load? (By "better", I'm looking at two key performance indicators: how well does it heat, and how much fuel does it use). Or are the numbers close enough that it really doesn't make a difference?


It's dead, Jim

@ November 14, 2009 11:45 AM in Water leaking from burner. Not good.

Hi Rod,

I was hoping to get a few more seasons out of the beast, but it's not to be.

I bought "Lost Art" shortly after I moved into the house. It's been an invaluable resource over the years, and it's sure to pay for itself again as I go thru the process of getting a new boiler. I'll be interested to see if my own calculations of the connected radiation are in line with the suppliers'.


Water leaking from burner. Not good.

@ November 14, 2009 7:38 AM in Water leaking from burner. Not good.

I have a one-pipe steam system, with a one-off steel jacketed boiler is almost 20 years old. Have had the boiler serviced by the same oil service company every year since we've been in the house (10 yrs).

This year a new guy came out, and after a couple hours and a lot of phone chat with his office, he was only able to get one of the baffles out of the tubes. Four days later, another guy comes out who'd previously worked on the boiler, and he had it apart and the baffles out in 10 minutes. He called me down to show me water around the frame for the access plate, and said there was a crack somewhere. Didn't seem too bad (famous last words), so he buttoned it up and I scheduled an appointment for one of their guys to come out to quote a new boiler.

Well, this morning comes and no heat. Went down to take a look, and there's water dripping from the bottom of the burner.

Seems awfully suspicious to me that there's this major leak soon after the first guy (who clearly wasn't familiar with this unit) works on it. What're the chances he screwed something up? Any way to tell for sure?

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