Many questions from a first time gassifier installer with 2 500 gallon stacked propane storage tanks

[gogreen2003]

I've been reading the posts on this board for a few months. This is my first wood boiler (gassifier) purchase and first foray into plumbing and heating system installation. I am attempting to heat a 3,000 square foot house (2,000 upstairs, 1,000 downstairs) and a 1,000 square foot pole barn in Northern Michigan (as soon as possible). Both the house and pole barn are in the process of being insulated with 2lb. closed cell spray foam. The boiler will be kept in the same room as my existing oil burning heater (in between the house and garage).

I decided on purchasing a NextGen BioMass Gassification Boilers» BioMass 40 from Zenon at New Horizon (will be ordering this Monday). I've already purchased 2: 500 gallon propane tanks from a scrapyard ($250/each). All the fittings on the propane tanks are the standard ones that come on all 500 gallon tanks (can post pictures if necessary).

I'm in the process of cleaning out my tanks by filling them up with water and Oxyclean (there is only a faint smell of propane left inside) and letting them sit for a few days before draining (far away from my well).

I am picking up a pallet rack to stack my propane tanks on top of each other.
It should look just like: stee6043's setup: https://www.hearth.com/talk/threads/44600/

In fact, my entire setup should be very similar to stee6043's (except I'm not using forced air).

Now that I am ready to install my system, I have a few (many) questions.

Questions:

1. What is the best way to attach the two propane tanks to each other? I would like to be able to use as many existing fittings as possible to do this, but am not sure if that is a good idea.

I will be spraying 3'' foam on my tanks very soon so I need to figure out exactly how many fittings I need for my system and where to install them. I figured that I need two fittings for each tank:
1 water in
1 water out

In addition, I will need fittings to connect the tanks to each other (above). I know that I want my cold return water coming in at the bottom of the bottom tank and the hot supply water coming in at the top of the top tank, and that I want as little mixing and turbulence between the hot and cold water as possible. I am just not sure how to achieve this with my two propanes tank stacked on top of each other setup.

I want to get the fittings situation sorted out asap so I can make an appointment with a welder to get them taken care of (and then I can spray the tanks).

2. I am in the process of compiling a list of all the materials I will need to complete the job (I want to do the simplest install possible). This is proving to be a bit overwhelming. I am currently going off of schematics and pictures of similar system I have found on this message board. Is there any comprehensive (or close to it) list of materials on a thread on this site (knowing full well that each install is unique) that could be used for my install?

3. I plan on working on this install with a friend (who has some plumbing experience) full time (starting Monday), any estimates on how long I can expect this job to take (I was shooting for a November 1st completion date)?

4. I have a 75' supply line that will run from the house to the pole barn. I plan on digging a 2' trench and insulating the supply lines with 5'' of closed cell spray foam. The surrounding ground is mostly sand. Is this deep enough? Do I need to wrap the foam covered supply lines in a plastic coating or can I just bury them as exposed foam?

5. It looks like ebay is the best (cheapest) place to purchase most of the equipment that I need for the install, is that a fairly accurate statement?

I know that this message covers a ton of ground, but really any help at all would be greatly appreciated.

 

[leaddog]

sent a PM
leaddog

 

[Hunderliggur]

Hope I can explain this well enough based on my setup (similar to yours, but with specific 2" fittings welded to the top and bottom of each tank (not using the dip tubes). I have 1 1/4 main lines for supply and return. Each line is T'd and goes to both tanks, with a ball valve in each line for each tank. This allows me to balance the supply and return between the two tanks. That bascaly describes the main loop (boiler to storage). For the heat exchanger, I draw from the top tank (hottest, you could do this with the main lines if you put a check valve in the feed to the bottom tank) and return to the bottom tank. Your underground line sounds like it will freeze in Michigan. You should put it at whatever your frost line depth is (same as a foundation depth). You don't want your underground lines to freeze when you finally go on that one week Hawaii vacation in January! You should also provide for a vent on the top of the tanks (to bleed air) and a drain on the bottom (in case you ever need to work on the tanks). Hope this helps. I have pics of my setup if you need them.

 

[stee6043]

Questions:

1. What is the best way to attach the two propane tanks to each other? I would like to be able to use as many existing fittings as possible to do this, but am not sure if that is a good idea.

I will be spraying 3'' foam on my tanks very soon so I need to figure out exactly how many fittings I need for my system and where to install them. I figured that I need two fittings for each tank:
1 water in
1 water out

In addition, I will need fittings to connect the tanks to each other (above). I know that I want my cold return water coming in at the bottom of the bottom tank and the hot supply water coming in at the top of the top tank, and that I want as little mixing and turbulence between the hot and cold water as possible. I am just not sure how to achieve this with my two propanes tank stacked on top of each other setup.

I want to get the fittings situation sorted out asap so I can make an appointment with a welder to get them taken care of (and then I can spray the tanks).

2. I am in the process of compiling a list of all the materials I will need to complete the job (I want to do the simplest install possible). This is proving to be a bit overwhelming. I am currently going off of schematics and pictures of similar system I have found on this message board. Is there any comprehensive (or close to it) list of materials on a thread on this site (knowing full well that each install is unique) that could be used for my install?

3. I plan on working on this install with a friend (who has some plumbing experience) full time (starting Monday), any estimates on how long I can expect this job to take (I was shooting for a November 1st completion date)?

4. I have a 75' supply line that will run from the house to the pole barn. I plan on digging a 2' trench and insulating the supply lines with 5'' of closed cell spray foam. The surrounding ground is mostly sand. Is this deep enough? Do I need to wrap the foam covered supply lines in a plastic coating or can I just bury them as exposed foam?

5. It looks like ebay is the best (cheapest) place to purchase most of the equipment that I need for the install, is that a fairly accurate statement?

I know that this message covers a ton of ground, but really any help at all would be greatly appreciated.

First off, welcome! I think you'll enjoy the install. It's a challenging but fun process.

I'll tell you how I did mine:

1.) I had (4) stock connections in each of my tanks (on top). I used the 1-1/4" to install a 1" dip tube to within 3" of the bottom for return. I used a 1" connection for supply right off the top. I installed 3/4" ball valves on the other two fittings to make filling the tanks easier (as well as getting the air out). I ran supply from my boiler to supply on the top (upper) tank. The return from the upper tank plumbed to supply on the lower tank. And return from the lower tank went back to boiler return. Make sense? They are plumbed in series, in other words.

2.) Your material list will change daily. My best advice is to start installing and get an account online with grainger.com. They have all the crazy nipples and fittings you could ever need and they usually ship within a day. For starters - get a lot of pipe dope, some teflon rope and (10) nipples of every length. Have you decided on pipe size? I used 1-1/4" and I'd say this would be the minimum for you as well. Menards is a good local source for your flue requirements. They also have pretty good pricing.

3.) Yikes, I think the last thing you want to do is rush your install. Take your time, drink some beer, and think while you do it. I started my install in August and didn't have my first fire until January 1st the year I did mine. It's a lot of work. Although I did mine 100% solo except for the heavy lifting. And I'm not a plumber.

4.) In my area code to get below frost line is 42". I think you're going to need to go deeper. Someone else will have to chime in though since I haven't buried any pex in my days.

5.) Patriotsupply.com is good too. I used pexsupply.com for a lot of my material but their customer service was terrible. I wouldn't recommend them.

 

[stee6043]

If you want to see more photo's of my setup I did a "summary thread" back when I completed it...

https://www.hearth.com/talk/threads/32524/

 

[Tennman]

I think you'll like the BioMass. But heating a total of 4,000 sf sounds more like a BioMass 60 vs 40. No idea of your insulation etc. We heat 4,800 sf with a 60. Might want to get more feedback here on the boiler size. Zenon is certainly knowledgeable about what size is heating how much space. Hopefully others will chime in here, but typically a 40 class boiler heats a smaller space. Request input from others here.

 

[Tennman]

Heck yeah to what Stee said..... I just answered a post about my experience with fittings and pipe compounds. Read the sticky about my painful journey doing the underground part. On the underground install, the only reason I placed the plastic in the trench was to prevent the foam spray gun from blowing dirt into the foam. After the pipe is foamed the plastic doesn't serve any purpose. I just threw it over the foam the pushed the dirt on top. In hindsight, if you only plan on heating your upstairs I guess the 40 sounds about right. Lots to learn here.

 

[stee6043]

I think you'll like the BioMass. But heating a total of 4,000 sf sounds more like a BioMass 60 vs 40. No idea of your insulation etc. We heat 4,800 sf with a 60. Might want to get more feedback here on the boiler size. Zenon is certainly knowledgeable about what size is heating how much space. Hopefully others will chime in here, but typically a 40 class boiler heats a smaller space. Request input from others here.

Some days I wish I had a 60, myself. It would just make heating my tanks quicker!

 

[gogreen2003]

Wow! Thanks everyone for the replies.

Hunderliggur: I'd love to see pics of your setup. If I understand correctly, you cut 2: 2'' holes into each tank: one on the top and one on the bottom. For a total of 4 2'' holes? Did you use black pipe? I'll likely have more questions once I see the pics, but I'll wait until then so I can understand a bit better.

I'll dig the trench deeper as per the advice. I'm looking into the frost depth line.

stee6043: I think I want to plumb in a series as you described. The separation between the tanks should minimize turbulence (mixing of the hot and cold tanks), right? If I understand that setup correctly, the two tanks are connected to each other and act as one large tank, correct? The tank on the bottom has the return for the cold water coming from the house and pole barn and and the cold water supply for the boiler. The tank on the top has the return for the hot water coming from the boiler and the hot water supply for the house and pole barn. You only used one 1'' connection to connect the tanks together? The dip tube you used went into the bottom tank and went to 3'' from the bottom of that tank, right? This was taking the coldest water in the system and putting it in the bottom of the bottom tank, right? The dip tune had nipples on it to diffuse the water and not mix the cold water with the warmer water, correct?

Your one Man's EKO 40 install thread is really great.

Tennman: Ideally, I'd like to go up to the 60, but cost constraints means I'll have to make due with the 40. I am hoping that the 1000 gallons of storage plus good insulation will get me through. The pole barn has been sprayed with 1'' closed cell foam on the walls and 2'' on the ceiling. The house is partially sprayed as well.

Question: One the tanks are cleaned out and I have the fittings I want welded on them, I can go ahead and insulate the tanks with spray foam (even though they won't be pressurized or plumbed yet), correct?

Question: I was thinking of using 1' 1/2'' pipe lines for the supply/return to the boiler from the tanks (tanks and boiler will be about 15' apart). From what I'm reading, this should be okay, right?

I was then thinking of using 1'' supply/return pipe lines for the pole barn to the tanks (which will mostly be buried underground). This should be sufficient, right?

The boiler will be placed right next to the existing heating oil boiler so I should have very little piping to hook into the existing heating system for the house. I figured 1' 1/2'' pipe for this as well.

 

[gogreen2003]

Additional question:

Would it be possible to use JB Welds for the additional fittings I need to cut on the propane tanks? I know that this is probably a less than ideal solution to the problem, but I am looking for something that could potentially save me some time and money. I am currently trying to figure out what size and how many fittings I need welded on my tanks, but haven't lined up any welders or received any estimates on how much this might cost. From the limited information I have received, it looks like each fitting weld might take up to an hour, and I will need to have 6-8 fittings installed. I've been told it costs $35-$50/hr. to hire welders in my area. That would put my cost at $215-$400 for the welding on the propane tanks. Does that sound accurate?

I've read that JB welds can withstand temperatures and pressures that far exceed those that will be running on my system. I am looking for them to last up to 5 years. I have made no decision on this, just wanted to see if anyone out there has any opinion on the matter or experience with a similar application.

 

[Hunderliggur]

Pics of my Paxo 40 w 2x500 storage are here https://www.hearth.com/talk/threads/49009/ . Mark at AHONA welded the tanks for the fittings and stacking rack (I am not a welder). I also have 3, 4" fittings for in tank heat exchanger for DHW and (future) solar input. The third fitting is a "bonus" ;-) (I think Mark made a mistake) but I'll find a use for it, maybe a coil for a walkway snowmelt? I would find a welder, not use JB Welds. Try to find a fix price deal at what you are willing to pay, but pay a fair price. If you don;t rush the welder you may find someone willing to pick up a couple hundred of bucks after normal work hours. Ask around.

 

[Tennman]

Not only no... but heck no on the JB weld! Not that it'll be so dangerous WHEN it lets go, but it absolutely will eventually let go. In our manufacturing business we rarely trust a structural epoxy to metal bond. Structural bond meaning it sees real loads and bad stuff happens when it lets go. I'm not going to go into differential thermal expansion leading to bond line failure. Geez this is a pressure vessel even if the pressures are low. It's really about two dissimilar materials expanding at different rates. A crappy weld is better than a great epoxy bond. I need to go split wood.... soon it will be below 95F out there. Now if you make those tanks out of titanium.....

 

[stee6043]

stee6043: I think I want to plumb in a series as you described. The separation between the tanks should minimize turbulence (mixing of the hot and cold tanks), right? If I understand that setup correctly, the two tanks are connected to each other and act as one large tank, correct? The tank on the bottom has the return for the cold water coming from the house and pole barn and and the cold water supply for the boiler. The tank on the top has the return for the hot water coming from the boiler and the hot water supply for the house and pole barn. You only used one 1'' connection to connect the tanks together? The dip tube you used went into the bottom tank and went to 3'' from the bottom of that tank, right? This was taking the coldest water in the system and putting it in the bottom of the bottom tank, right? The dip tune had nipples on it to diffuse the water and not mix the cold water with the warmer water, correct?

Your one Man's EKO 40 install thread is really great.

Tennman: Ideally, I'd like to go up to the 60, but cost constraints means I'll have to make due with the 40. I am hoping that the 1000 gallons of storage plus good insulation will get me through. The pole barn has been sprayed with 1'' closed cell foam on the walls and 2'' on the ceiling. The house is partially sprayed as well.

Question: One the tanks are cleaned out and I have the fittings I want welded on them, I can go ahead and insulate the tanks with spray foam (even though they won't be pressurized or plumbed yet), correct?

Question: I was thinking of using 1' 1/2'' pipe lines for the supply/return to the boiler from the tanks (tanks and boiler will be about 15' apart). From what I'm reading, this should be okay, right?

I was then thinking of using 1'' supply/return pipe lines for the pole barn to the tanks (which will mostly be buried underground). This should be sufficient, right?

The boiler will be placed right next to the existing heating oil boiler so I should have very little piping to hook into the existing heating system for the house. I figured 1' 1/2'' pipe for this as well.

You have it right. My tanks act as "one big" tank the way I have them plumbed. It's quite simple.

I wouldn't do any spray foaming until you're 100% done, had a fire, tested everything at operating temperatures.

1-1/2" pipe would be great for your near boiler piping. The 1" for your pole barn run depends a little on distance and what the water does when it gets there. Can you provide more detail?

And like said above - JB weld is not intended to patch/repair pressure vessels as far as I can tell. Only use real welding on actual joints. If you need to attach pipes to the inside of nipples (for a dip tube for example) on the inside JB weld would work fine. But not for an actual fitting/connection.