1930's VECO Vapor System. Boiler change and system upgrades.

JStar

Next week, we'll be replacing the steam boiler on a 1930's Vapor Engineering Company two-pipe system. We're going with a tandem arrangement; two boilers staged on both a two-stage thermostat and pressure. Each boiler will be fired at 60% of the total load, and alternate between being the High and Low fire boiler. We'll also be attaching a small baseboard loop and indirect tank to the high fire boiler, so we expect the run times to be fairly close to each other.



We'll be removing all of the radiator traps and installing orifice plates in each supply pipe (much thanks to Tunstall; their customer service is incredible).



The original venting is just a pipe in the chimney, as per the original VECO design. We'll be removing this and adding our own modern vents.



In the garage, we'll be removing a wall-hogging radiator and installing a new Modine steam unit heater.



There will be a bunch of other little odds and ends to repair around the system, as well as some custom made controls and goodies. I'll post pictures as the project goes on. Here are a few pictures of the original system.



<a href="http://www.heatinghelp.com/files/articles/1393/3.pdf">http://www.heatinghelp.com/files/articles/1393/3.pdf</a>

vaporvac

museum?

There really needs to be a museum for some of these old bits and bobs That water fill tank is amazing. They should save and display something from that old system.It actually looks pretty interesting; now I have something else to research someday.

Thanks for posting. Your new system sounds intriguing. Wish you lived closer to me. What boilers and burners and controls are you using? CTD

JUGHNE

Great Tunstall Service

I left my phone number with the Tunstall  receptionist to inquire about inlet orifices and assumed the usual maybe call back/maybe not.  I was amazed the next morning to get a personal call from Mr. T.P. Tunstall himself.  He spoke at length to me out here in flyover country and all I wanted was a small coffee cup full of orifices.  This just doesn't happen anymore... so I thought.  Most Wallie's are probably aware of Tunstall Service but I'm assuming there will be a lot of views of this original post so that's why I'm beating this drum.  Had I been aware I would have gotten their traps for this project.

Now a question; what orifice sizing chart are you using?  I am planning to use the Henry Gifford chart included with his article "How to make a 2-pipe steam heating system really work"  from BSE June 2003--Wall Library.

Thanks for help!! 

JStar

Museum

I would be at that museum every week!



We're actually going to be keeping the old Pressure Governor and setting it up as if it were brand new. The system will be its own museum for the next guy to enjoy...hopefully enjoy.

JStar

Tunstall

Really, a top notch organization. From phone calls to emails, the whole attitude and communication was fantastic. I ordered the orifice plates more than a month ago to give them plenty of time for production and shipping and they still called to apologize that they would be delivered a day later than promised.



Now, I'm just looking to use them on every two-pipe job, if possible.

JStar

Controls

The only fuel source available is oil or propane. We're sticking with oil and using Smith series 8 boilers with Carlin EZ-1 burners. The controls will be a combination of many. We'll be using a Taco 2-stage switching relay and zone control board, Honeywell WiFi Touchscreen t-stats, Honeywell Vaporstats for staging, and a custom item that I'm keeping secret until I know it works.

Dave in QCA

Tunstall is Excellent

I too used Tunstall orifices on my system. My purpose was for balancing. As it turns out, Dunham (my system is a Dunham) very strongly promoted the use of "regulating plates" to achieve balanced steam distribution during partial steaming cycles.



I was extremely happy with Tunstall's service whether it was during the initial order of 30 orifices plates or subsequent small orders when I was doing additional tuning of the system.



The system that you're working on here, J Star, looks very interesting and I look forward to seeing more pictures as you finish up.

JStar

VECO

Here's a link to the VECO brochure...



http://www.heatinghelp.com/files/articles/1393/3.pdf

BobC

Google books on Jenkins Disk

This explains the jenkins disc that was used on the radiator valves -



http://books.google.com/books?id=fdI6AQAAMAAJ&pg=PA83&lpg=PA83&dq=jenkins+disc+for+steam&source=bl&ots=3xrs_gFR5V&sig=eMIY3QOAhdXFqUKyOY9IcRL7wQI&hl=en&sa=X&ei=oIU9UvLsNtfG4APh5oHIAg&ved=0CFoQ6AEwBw#v=onepage&q=jenkins%20disc%20for%20steam&f=false





Bob

moneypitfeeder

Can't wait for more pics!

You're project looks really interesting, I can't wait to see pics as you progress. I too am a Tunstall fan, I want to go with orifices the next time I start to change out traps, but I have to say T makes the best replacement capsule traps that in my limited experience I've tried. Their traps fit in my old housing perfectly, and seated well when the cap was reinstalled. I tried another manufacturer, and the trap fit poorly, and spun when the cap was threaded on, made the seat wear on a horrible angle. I threw those out. To make that worse there wasn't much of a cost difference. I would choose tunstall's any day after that!Keep us posted on your progress!

JStar

Day 1

Old boiler out. New boilers in. Started the near-boiler piping. I opted for individual drop-headers on each boiler to guarantee dry steam production. After we convert all of the radiators to orifice plate supplies, I don't want anything else to lower their capacity. And we'll be staging the boilers at such precise pressures, that any wet steam might affect this delicate balance. Can't be too careful...or too crazy!



We also got 90% done with the indirect tank connections. We installed a flat plate heat exchanger to create a separate loop for the tank and a small baseboard loop.



Day 2 will have us tackling the existing header. We plan to break apart one of the elbows to allow us to configure it correctly. We should have both boilers and the indirect tank online and firing. May have some preliminary staging results if we are able to complete the control wiring.



Some of the photos are very dark. We'll post some better quality ones at the end of the job.



Going totally against my own principles, we will be removing the Pressure Governor at the customer's request. He understands its historical significance, but would rather remove it and eliminate a few points of potential failure in the system. We argued (mildly), but are now the proud owners of this beautiful piece of mechanical art. Just need to find a strong enough wall to hang it on. It's about 3 feet tall and probably weighs 150 pounds.

SWEI

That's a lotta screwed pipe

nice!

JStar

Day 2 and 3

Not much to show for Day 2. Today we finished all of the boiler piping and control wiring.

JStar

Controls

Here are the controls:



TACO SR-501-4-HC controlling the boilers staging



TACO ZVC zone control board with Domestic Priority



A custom made Runtime Hour Meter panel. These meters will log how many hours the thermostat stages are calling and how many hours the burners are actually running. I expect the burners to log close to half the hours that the thermostats do. This will also allow us to lead/lag the boilers every other year.



The boilers are staged via the two-stage thermostat as well as a set of Vaporstats. The low fire boiler runs between 1 and 8 ounces. The high fire boler runs between 3 and 5 ounces. I expect this to take a lot of fine tuning to get the staging perfect. Hopefully, we have enough time to play around with the settings before letting it run loose during the winter.

moneypitfeeder

Holy Rise!

That's a great rise before the drop header! You'll surely have dry steam outta that set up. From the original pics, I wouldn't have thought you had that much space to work with. Thanks for the update, I'm sure the owners of this system are going to be really happy with their upgrade.

JStar

Header

We had a lot of floor space available. More than I was having nightmares about the night before starting...



I really wanted to make both boilers drop into the system header, but the head room was being hogged by the existing mains lines. Still, we expect to achieve very dry steam.

JStar

Day 4

Started adding the baseboard loop to the basement. Will have it finished today. In fact, everything will be finished today! Now is the time to request pictures.



Yesterday, I removed all of the convector traps and installed the supply orifice plates. With about 3 inches of space to work in, my hands are scraped and sore. All in all, they went in easy. Looking forward to using them on a job with open radiators and plenty of room to turn a wrench.



Did some preliminary testing of the boiler staging with good results. Will retest everything today now that the orifice plates are in and main vents have been added.

JStar

Final

Job is complete. Everything working as well as expected. Now, we sit and wait for winter.



The boilers got all of the convectors hot about 15 minutes from start-up. Even rooms that never got warm with the old system. The system is whisper quiet. I had my worries about the orifice plates (potential water hammer in returns), but everything was smooth and silent.



The pressure was hovering just over 1 ounce for about 30 minutes, with no major increase.

JStar

More

Thank goodness for stair climbers and lift gates.

SWEI

That's not a vent tree

...it's a small grove!

JStar

Vents

Big system. Big vents,



The system had three 3" mains, 24 convectors, and about 60 feet on the longest return. End of the mains hot within 10 minutes from cold start.

Dave in QCA

Orifices nice and quiet

I have found that the orifices themselves create a small amount of sound. It is a steam velocity sound... sounds like steam going through an ---- an orifice. Can't think of any other way to describe it. As for the rest of my system, it became silent. No water hammer, no clanking, and as a result of piping corrections in the boiler room, expansion sounds such as a LOUD bump at the beginning of each cycle all completely disappeared.



AND... very nice looking install! What is your operating pressure range? What pressure does the lag boiler cut in, and cut out?



I would imagine that you are seeing steam arriving all of the convectors at the same time.

JStar

Pressures

We sized the orifices at 8oz. With piping and friction loss in mind, I set the Low Fire / Operating pressure between 1 and 12 ounces. The high fire boiler cuts out at 8 and cuts in at 4. During testing, it ran for 45 minutes without going above 1 oz. I'm guessing that we'll be relying on the 2-stage thermostat more than the Vaporstats for staging.



Every room in the house was getitng heat at relatively the same time, with just 2 out of 24 rooms falling slighlty behind. May need some adjustment with orifice sizes. The convectors are hard to measure, and I took my best guess at their size.

Dave in QCA

one boiler?

Was that running time where you stayed at around 1 ounce, running on one boiler or two? And, I apologize if I have overlooked this, but what is the total EDR rating of the orifices, and what is the Gross Output of the boilers? Not Net, Not boiler EDR. I'm assuming all of the mains, runouts, and risers are insulated.

JStar

Pressure

Yes, running time with both boilers.



Orifices are degraded to 85% EDR capacity. Total EDR was around 965. So, with the orifices, that makes 820. Boilers firing at 150K each (60% of total load). Boiler output is 127K DOE, 115K NET.



Only added 10% pickup factor due to orifice plates producing less start-up condesnate and heavy pipe insulation.



I feel the long run times with low pressure are due to a large amount of dry returns, and the fact that there are no longer traps to close the return, and cause immediate back pressure.

Dave in QCA

Something not quite right

Joe, I have checked your numbers and I see no error. I don't remember if your mains are vented with a main vent or a crossover trap. Either way, what you should be observing is that shortly after the steam gets to the end of main and closes the venting device, the pressure in the mains (between the boiler and the orifice plates) should begin to rise. It should rise fairly quickly over the course of 2-3 minutes until the steam going through the orifices is equal to the steam coming from the boiler, minus 10% due to piping loss, or condensation within the steam main and risers. Length of firing time should have no effect on the pressure after main pressure is established because the convectors are separated from the steam mains by the orifices and they will never build pressure. The only way they would ever build pressure, as you have removed the traps, is if they were being supplied with a greater amount of steam than their capacity, in which case it would fill the return lines with steam and cause the vents on the returns to close. If this happens, then the convectors will pressurize, which would reduce the flow rate through the orifice plates, which would cause the steam main pressure to also rise. Otherwise, the boiler and steam main pressure should remain constant after the initial heating and pressurizing of the main.



I am sure that you have clocked the meter to confirm firing rate and have got the burners tuned properly. So, I can't think of to many other things that could have gone wrong. Is it possible that a convector or two got overlooked and didn't get an orifice? Perhaps an orifice slipped out of position?



I would expect your setup to be able to establish a main pressure of about 8 oz with both boilers firing. With one boiler firing, I would expect to see a pressure of 2-3 oz. Thus, this was my initial question regarding whether one or two boilers were operating.

Dave in QCA

Ahhh! Domestic!

When you were running your initial firing and pressure was staying down around 2 oz., was your domestic HW system heating at the same time? That WOULD throw things way off!

JStar

Pressure

Yes, the indirect tank may have been calling for temperature.



I'm also thinking that the low pressure gauge may be off a little. It is possible that we had at least 1 or 2 ounces of pressure more than what I thought. It's funny. The first day we ran it, we gained about 4 ounces of pressure within a few minutes. The second day we ran it, it never built pressure. We also installed a unit heater in the garage that I chose not to install an orifice in. My thinking is that when the fan is not running, the orifice will be grossly oversized. It has trap on the return.



There are no vents on the steam mains, only on the return mains. All steam mains end in a wet return.

Dave in QCA

something causing the difference

Joe, the fact that you got 4 oz one day and hardly anything at all the next says that something is not quite right. I'd recheck the burners, re-clock the meter, check with domestic turned off. See what you get then.



Yes, I saw the install of the little blast heater and noticed the trap. I think you are OK there with or without an orifice. As you point out, even with an orifice, when the fan is off, you got to have a trap there to keep the steam out of the return.



In your case, since you have no steam main vents, the pressure should rise as soon as the steam gets to the end of the main. During the start up, when the steam is running out into a cold main, simply raising the temperature of the main will condense all of the steam and prevent pressure from rising. As the steam gets to the end that condensation drops way off, hopefully to no more than 10% of the total steam. Then the pressure will begin to build until the steam going through the orifices and the steam coming from the boiler are in balance.



For a low pressure gauge, I prefer a 3 LB gauge. It will let you accurately see the ounces.

JStar

Pressure

We have a 2 pound gauge on the header near the Vaporstats.



I'll have to apologize as to my fuzzy memory. It was a long week!



I'm sure I'll be going back to fine tune a few aspects of the system at some point. I'll document the run cycles and pressures again. Maybe throw a second pressure gauge on.

Dave in QCA

Let us know

Let us know how it all turns out. It sounds like it is going to be a great system and is sure to save the owner a LOT of money. And, he's going to be very comfortable with very even heat.

JStar

System

The homeowner is going to send us his oil bills throughout the year. We're expecitng to see some major savings.



Between using the orifice plates and some new control arrangements for the first time, this job has a bit of a learning curve for me. I appreciate all of the input and advice.

gerry gill

Thats one very pretty install, Joe

exceptionally well done!