Feed Line/Backflow Preventer question

[dogwood]

I am trying to understand how the feed line and pressurizing process works in utilizing BioHeat's PT3 piping layout, http://www.woodboilers.com/uploads/public/PressureTank(PT3).pdf. I have purchased a Watts Series 009QT reduced pressure zone backflow preventer for the system's feed line. In the piping diagram there are ball valves located before and after the backflow preventer in the feed line. The 009QT has one ball valve connected to either side of it so I think I'm good to go there. I am confused about whether either or both of the ball valves are to remain open or closed after the entire system is initially filled with water and purged of air.

If one or both are closed what would be the function of the backflow preventer be then? Does it have a use only while filling the system with water? If both ball valves are left open wouldn't the pressure remain the same between your homes water supply and your boilers? I know that's not wanted. I had hoped to start the boilers system pressure at 12-14 psi at 60 degrees and maybe 20 or so psi at full system temp of 180 degrees. I had originally thought that the backflow preventer would automatically let makeup water into the system during the normal course of business, if there was any need due to air being purged. Maybe not, if those valves are to be closed to keep the house water pressure separate from the boiler system's water pressure.

If it would help to look at my backflow preventer here is the link to see it, http://s3.pexsupply.com/manuals/1249544537780/009-spec.pdf. Maybe you have to open those ball valves only periodically to let in makeup water. If anyone knows how this is supposed to work please help me understand this better prior to my starting to install the whole system. Thanks.

P.S. You'll need to copy and paste the first link into your address bar in order to make it work. The last three letters didn't turn purple for some reason.

Mike

 

[Eric G]

Dogwood Im pretty sure that valve is exactly what it states. Its not a pressure regulating valve. If you close both ball valves can the valve itself be taken out for maintenance? That would let you stay online.Do you have any pics?

 

[Eric G]

The other thing is I dont know what your system layout is.usualy backflow prevente4rs are used so you dont back syphon or form an overpressure that would backfeed into your drinking water. How are you getting your supply water?-Do you feed it through your expansion tank via a T? Watts makes a prv and check all in one. Thats how my system is set up. without the check on my supply I could end up drinking my boiler water-EISH. Anyhow thats code around these parts.

 

[flyingcow]

When i had my system installed, per tarms diagrams, we did not put another water feed in to the system, we ignored that part. We just used the one of the existing oil fired system that was here. I have filled the entire system with that. Also i had to replace a valve since then, and got air into my heating system(thats another reason for me to wait for the installer to return), but i used the existing fill valve and every thing worked fine. That is a long way around, to thinking you are supposed to leave ball valves open. The ball valves are there only for having to replace valve, if needed. I have about 20lbs when my wood boilers cooking. Everything works fine. When I was refilling my system, after replacing valve, i dumped a bunch of water out the pop off pressure valve. OOps. My refill valve has a little lever on it to open the valve up to house line pressure. I left it open, but luckily was right beside it. Once I closed the little lever, water stopped p!ssing out the pop off valve. Hope this rambling story helps. BUT hopefully someone else will chime in. Like heaterman.

 

[Eric G]

Ok I looked at the pdf. That valve im assuming is half inch correct? Anyhow if use the watts part number B9-11SM3-that should solve your problem.Its a backflow preventer/boilerfill kit-union by sweat. Im just suggesting.That bfp seems to be a little overkill in my opinion.That part number I gave you is pretty much standard fare. You can bypass the prv via a lever for full line pressure as flyincow stated. Just dont forget to close it or your hi hats will be going pee for sure.

 

[Eric G]

If you wanted to keep the existing backflow preventer you could just add A watts 1/2" S1156 F STD which is a pressure regulator. They have them right at the depot and arent all that expensive. Just put a 1/2" ball valve before this then the prv then your existing backflow preventer and another ball valve so you can isolate it if need be.That backflow preventer is designed to be used in a reduced pressure system.Hope this helps.

 

[dogwood]

Eric, I will look up that Watts part you suggest. The 009QT is a 1/2 inch valve which feeds off the house's regular water supply through 1/2 inch copper pipe. The expansion tank is to be teed off the same line after the bpf. Maybe I made my question too confusing? Thanks Flyingcow, but I am still confused about what would keep the house's water pressure separate from the boiler systems if I used the BioHeat diagram and left the ball valves open after filling the pressurized system with water. I do not have an alternate water feed as you had in place. Eric I am sure you are probably right about the bfp I selected being overkill. I didn't want to take any chances on contaminating or polluting my houses well-fed water supply. I also did not want to leave any question in the inspector's mind about negatively affecting the potability of our wells drinking water.

I was originally going to fill my system with a garden hose and not permanently connect it to the houses water supply. Then I thought I'd better follow BioHeat's suggested PT3 design as closely as possible to avoid any problems through my own ignorance of how things hydronic work. The chances of an amateur like me second-guessing and out-guessing professionals in their own field would not be good. The BioHeat techs who design their plumbing schematics techs seem to know what they are about.

Mike

 

[dogwood]

Eric, you know I just read in a previous thread about the pressure regulator you mention. I was considering doing just that but never heard of such a device before. Since you suggest it, sounds like a very helpful, and excellent suggestion which should solve the problem. I wonder why there isn't one in the BioHeat PT3 design? By the way the 009QT bfp is rated at 175 psi and 180 Degrees. I'm not sure why they would consider that reduced pressure. I thought maybe the reduced pressure would be the projected 12-25psi on the boiler side. There must be something here I'm not grasping.

If I do use a pressure regulator what psi should I set it at? The one you mentioned goes from 25-75psi. Anybody else have any input, or should that be the way I go. Thanks again.

Mike

 

[Eric G]

Mike if you install that it will be cheap insurance--kinda like a double check-you have the bfp and if you use that you will also have a check before the prv. What is the water capacity of your boiler? Are you using an oil boiler for a backup? The other thing Id like too mention is the expansion tank being sized correctly. Not enough cushion will lead to some over pushin LOL! Some ppl think that the one on there oil boiler will take up the added volume.Well more often than not this isnt the case.I couldnt see the diagram on that link u put up.If I could see it -well maybe I could help.

 

[Eric G]

Mike there are two part numbers-I gave you the higher one sorry--they make one that runs at 12-15. Thats the one you want.Sorry my bad.15lbs is good-12 is even better. Easier on the system. Like I said if you experience higher pressures chances are your expansion tank might be a bit small.If u get the one that runs at 15lbs you can just simply install it--no setting is required-there set at the factory.

 

[dogwood]

Eric, I just found the second one you mentioned on PexSupply.com. Thank you so much. I've got a fairly large expansion tank, an Extrol 86 gallon and another 14 gallon just to be on the safe side with 1000 gallons of storage, so I think I should be okay in that regard. Thanks again.

Mike

 

[Eric G]

A thousand gallons of storage? Ok im jealous. I cant even locate 500 gallon tanks. I drive by the gas companys looking at there boneyards full of 500 gallon tanks just sitting there. You inquire about purchasing one.You'd have a better chance of putting hell out by throwing snowballs into it. Guess they would rather let them rot away-go figure. Well it sounds as though you are off too a very good start. My woodboiler lays idle in the barn all cold-such a pity.Im not gonna pipe it directly to my oil boiler though.Yup I got patience-good thing too lol. Although I could because it has an 80 gallon water capacity but I dont want too run it like that.Hot-cold-hot-cold. Really not good for them. Burn it hot till your storage is up too temp and SHUT IT DOWN! lol.I guess im the first person in this area too have a downdrafter. All my friends are pipefitters like me-lots of skeptical ppl so failure isnt an option. The opinions do fly here I must say. Truth is my boiler is used but I got it for a fraction of the cost "BUT" and there is always one in the crowd"you could have bought two effecient package oil boilers for what you paid for that thing". My reply is-Yup I could have but I didnt so whats your point? Am I in trouble? Hell im 43 go home and pick on your wife or your kids lol! Anyhow I hope your system runs smoothly for you and im glad too help in anyway.

 

[dogwood]

Eric,

You'll find that 1000 gallon tank if you keep looking. I got mine by word of mouth. I'd been searching on Google, Craiglist, and asking anyone I thought might have a lead. Earlier threads mentioned a couple places in Pennsylvania that would sell to private individuals. A propane dealer in Roanoke I enquired of knew of a Feed and Supply store that had a slew of them. Virginia is too far away for you. I had a lead in Kentucky and a dealer in Kansas who had hundreds, but that was way too far away. If you're adventurous, desperate enough, and have a big truck, the store in Staunton, Virginia had them on trailers (no extra cost) ready to roll away. If I remember its 10 or so hours to Rhode Island from here. Paid $800.00 if I recall. Good luck on finding yours. Still have to sell the 18 or so foot trailer, which will help defray the initial cost. Try this link, https://www.hearth.com/econtent/index.php/forums/viewthread/38641/ for a picture.

What kind of boiler did you get?

Mike

 

[flyingcow]

I see your pics of the tank. $800 is a good price, with the trailer. I didn't look to see where is VA, but it seems to me it would be less than 10 hrs. Get a couple of buddies and yell. Road Trip!

 

[Eric G]

Thanks for the link Mike and yah I might be that desperate.Its not getting any warmer here for sure. I bought a Woodgun E 180. Its a certified vessel (A.S.M.E)-also a steam boiler. This one has an oil gun also but I dont plan on using it. This thing is built like a brick Sh*t house. 2,200lbs dry. Its a carbon steel unit. I know they came out with 304 stainless fireboxes later on but this boiler is all there. I have a friend who does non destructive testing. They use the same technology on steel as they do on humans lol. They use a sonar device and gelly-just like when they determine gender in an infant before it is born. The material in the firebox (which is where they fail) only showed a 1/64 under spec. Its 22 years old and probably the most mechanical wood gassifier you can buy. It basicaly runs off a triple aqaustat , a fan and a dc servo.I timed it and when there is a power loss that intake air servo closes like a bear trap-well almost-6 seconds.Thats a true story. The other wood boilers I have installed (updrafters with a secondary burn) have heat actuated mechanical damper and require an over heat loop attached to a mag valve in the event of a power loss. In other words they get warm before closing down. Without it they would blow off and somrtimes do. Sometimes they do a little irish jig if there not anchored to the floor.Oh yah this one has a dhw coil too. Umm I brew beer from grain and there is a brewery in the making. I wont need that coil so it will be used as a supply for my brew pot lol. shhhh! Im really interested in 2 500 gallon tanks though. My barn has limited space and I would like to fit(cut them down a bit) and place them verticle in series on a manifold. Im still looking though. Maybe something will pop up. I can get all the 250's I want but it wouldnt be enough volume.Id end up with 480 tops-not worth it.

 

[flyingcow]

Eric G, I'm assuming you're going to do a pressurized storage?

 

[dogwood]

Good luck with both your Woodgun install, and beer brewing too. Sounds like you've got the skills to get the installation done. And it's not just anybody who can make beer out of wood gassifier parts. Some older threads mentioned people cooking in gassifiers. Its obvious you and they need to combine your skills.

Eric, you aked what is the water capacity of my boiler. Its a Baxi (Tarm) Solo Innova 50, like yours, awaiting installation. It holds 48 gallons of water according to the manual. I don't have a boiler for backup. I'll be using my Lennox Pulse forced hot air for that purpose. Anyway, if nobody disabuses me of the notion, I'll be getting that pressure regulator ASAP. Thanks too Flyingcow. I'll see if I can fix that link in the first entry. (PS: It needs to be copy and pasted in is entirety in your address bar to work)

Mike

 

[flyingcow]

Dogwood, wasn't paying attention, didn't know you were doing the Innova. i just fired my Innova 30 up a few minutes ago. I'm using the loading valve that tarm recommended, actually I'm using about everything they have in their layout. Kind of a sucker , but the system does work well. My boiler was about 80f and it should be shipping 155f to my house in about 30 minutes. It'll jump to 180+and keep rising quickly. Using the TV-1 that they supplied, this will ship water to my house zones before the storage. Nice feature. my baseboard was set up for about 160, so when the 180+ starts rolling thru, heats up quick. Whatever heat the house doesn't need, it'll dump in the tank. The draft is nice on this unit, if you need to open the loading door at any time, minimal smoke roll out. Good luck

 

[dogwood]

Flyingcow, I'm encouraged yours works so well. I'm hoping to start installing in the next week or two. Did you run into any problems with your install. Any advice? Did you put yours in yourself? Like you, I'm using everything BioHeat recommends in their diagram, with the exception substituting one motorized ball valve for a zone valve, since I have 1.5 inch pipe and didn't want a restriction. Most zone valves I could find only go up to 1.25 inches.

I have only two zones, one for the W/A hx above my furnace and one for the W/W hx for my DHW. Next thing I have to figure out is will there be any problem created by either of these two zones utilizing very different gpms, 12gpm and 5gpm respectively, since the BioHeat diagram is not a primary/secondary system, but instead uses parallel piping, zoned with circ pumps. The pumps I am using have integral flow checks which I hope will keep the heated water from heading in the wrong direction. Not sure how that will work when both zones are open simultaneously. We'll see. If anyone has a thought on that matter let me know.

Mike

 

[flyingcow]

I did not do my install. The heating guy that did has done these before. Didn't run into any problems that i recall. All i was basically doing was hooking into an existing oil fired baseboard system. Had a few minor bumps, but bioheat has been very accesible and worked thru it.

 

[dogwood]

Eric, if you're still out there, the Watts pressure regulator installation schematic said to install the pressure regulator between the bolier and the bfp, as opposed to before the bpf as you suggest which made more sense to me, do you think it makes any difference?

Mike

 

[Eric G]

Yes I will be flyingcow. Id love to build a jacketed system too be honest. Call me crazy it's ok

 

[Eric G]

Mike if thats what they say then it makes sense. You could still put another check upstream though. I think a check as soon as you come out of your dw is a good idea.

 

[dogwood]

Thanks again.

Mike

 

[Eric G]

Mike-hey I just came too my senses--an odd occurence! lol! you want that prv before the bfp. Thats how we got into this LMAO!