I read the postings here regularly and have a few welding/fabrication questions.
I'm installing a wood fired boiler in my home and need a hot water storage tank. Something around 500 gal and sized for entry through a standard doorway. That precludes a propane or other such type tank.
It has occured to me that maybe the local welding shop could fabricate such a tank but I am aware that there are issues with a rectangular pressue tank even though is operates at a low pressure of 10-12 psi's.
Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' in size mild steel. Bent corners, flat ends, closely spaced internal baffles/exterior bracing?
In article <jcnh64t0qlc1lcuqo4flcuun8f8up17...@4ax.com>,
ED <albieguyspaml...@yahoo.com> wrote: > Any thoughts appreciated. ED
Practically speaking, you'll do better to build an insulated box that will hold multiple prefabricated round pressure vessels that add up to your desired volume - or do what most of the commercial installs do - have an un-pressurized insulated hot water tank with a pressurized heat exchange coil or coils.
Rectangular is a lousy shape, and results in a lot of extra work - and finding a weldor qualified to work on pressure vessels is often a bit of a search, and costly when completed. I have such a pressure vessel, which I unfortunately only intercepted when the outer shell (it's a wood fired water boiler) was partly cut off by the folks getting rid of it (since they had set it up with no heat storage, it never quite worked right, so they were getting rid of it, and wanted to lighten the lift out - I would have happily hired riggers to get it whole, but too late).
It has an array of straps tying the flat sides together every few inches (and is a mere 15 lb vessel, as you intend). Would be a lot of welding - I'm just thinking to reuse the firebox in some non-pressurized or non-water (sand, perhaps) setting.
<LawrenceSM...@SOuthernVERmont.NyET> wrote: >In article <jcnh64t0qlc1lcuqo4flcuun8f8up17...@4ax.com>, > ED <albieguyspaml...@yahoo.com> wrote: >> Any thoughts appreciated. ED
>Practically speaking, you'll do better to build an insulated box that >will hold multiple prefabricated round pressure vessels that add up to >your desired volume - or do what most of the commercial installs do - >have an un-pressurized insulated hot water tank with a pressurized heat >exchange coil or coils.
>Rectangular is a lousy shape, and results in a lot of extra work - and >finding a weldor qualified to work on pressure vessels is often a bit of >a search, and costly when completed. I have such a pressure vessel, >which I unfortunately only intercepted when the outer shell (it's a wood >fired water boiler) was partly cut off by the folks getting rid of it >(since they had set it up with no heat storage, it never quite worked >right, so they were getting rid of it, and wanted to lighten the lift >out - I would have happily hired riggers to get it whole, but too late).
>It has an array of straps tying the flat sides together every few inches >(and is a mere 15 lb vessel, as you intend). Would be a lot of welding - >I'm just thinking to reuse the firebox in some non-pressurized or >non-water (sand, perhaps) setting.
Thanks, I was afraid that, i knew there had to be valid reason for not seeing anything like that commonly used.
Automotive radiators are a rectangular pressure vessel, and I know that on off shore rigs where space is at a premium they are used..
I have a 500 gal propane tank but would have to build something to hold it and then run lines ect. Where does the pressure tank have to be installed in relation to the storage tank? Tkns ED
> I read the postings here regularly and have a few > welding/fabrication questions.
> I'm installing a wood fired boiler in my home and > need a hot water storage tank. Something around > 500 gal and sized for entry through a standard doorway. > That precludes a propane or other such type tank.
> It has occured to me that maybe the local welding shop > could fabricate such a tank but I am aware that there > are issues with a rectangular pressue tank even though > is operates at a low pressure of 10-12 psi's.
> Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' > in size mild steel. Bent corners, flat ends, closely spaced > internal baffles/exterior bracing?
> Hydro test to 1.5 operating pressure.
> Any thoughts appreciated. ED
What is the operating pressure, maybe 100 psi?
If you go rectangular, you could do something like 3/8 or 1/2 tie rods on about 12" centers to greatly reduce the required plate thickness. But a 500 gallon "box" that operates at normal water pressures is going to require the involvement of a good engineer to be safe.
Another possibility might be using something like a bundle of up to 6" pipe. Unless ASME has changed, since the last time I looked (about 30 years ago), vessels less than 6" in diameter, or I think less than 5 psi are exempt.
>> I read the postings here regularly and have a few >> welding/fabrication questions.
>> I'm installing a wood fired boiler in my home and >> need a hot water storage tank. Something around >> 500 gal and sized for entry through a standard doorway. >> That precludes a propane or other such type tank.
>> It has occured to me that maybe the local welding shop >> could fabricate such a tank but I am aware that there >> are issues with a rectangular pressue tank even though >> is operates at a low pressure of 10-12 psi's.
>> Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' >> in size mild steel. Bent corners, flat ends, closely spaced >> internal baffles/exterior bracing?
>> Hydro test to 1.5 operating pressure.
>> Any thoughts appreciated. ED
> What is the operating pressure, maybe 100 psi?
He said 10-12 PSI.
> If you go rectangular, you could do something like 3/8 or 1/2 tie rods on > about 12" centers to greatly reduce the required plate thickness. But a 500 > gallon "box" that operates at normal water pressures is going to require the > involvement of a good engineer to be safe.
> Another possibility might be using something like a bundle of up to 6" pipe. > Unless ASME has changed, since the last time I looked (about 30 years ago), > vessels less than 6" in diameter, or I think less than 5 psi are exempt.
-- Due to extreme spam originating from Google Groups, and their inattention to spammers, I and many others block all articles originating from Google Groups. If you want your postings to be seen by more readers you will need to find a different means of posting on Usenet. http://improve-usenet.org/
> I read the postings here regularly and have a few >welding/fabrication questions.
> I'm installing a wood fired boiler in my home and >need a hot water storage tank. Something around >500 gal and sized for entry through a standard doorway. >That precludes a propane or other such type tank.
> It has occured to me that maybe the local welding shop >could fabricate such a tank but I am aware that there >are issues with a rectangular pressue tank even though >is operates at a low pressure of 10-12 psi's.
> Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' >in size mild steel.
I have a similar application, for a solar water-heating setup. Used (home made) copper heat-exchanger coils inside a rectangular tank fabricated from mild steel to hold about 80 gallons of hot water-glycol mix at 160F, zero pressure. Figured the corrosion inhibitors in the anti-freeze would prevent problems. After a year or so the flaking was incredible. Rebuilt it with stainless, no more problems.
On Jun 30, 9:31 am, ED <albieguyspaml...@yahoo.com> wrote:
> I read the postings here regularly and have a few > welding/fabrication questions.
> I'm installing a wood fired boiler in my home and > need a hot water storage tank. Something around > 500 gal and sized for entry through a standard doorway. > That precludes a propane or other such type tank. > Any thoughts appreciated. ED
How about two home oil tanks or ten 55-gallon drums?
I would NOT close the tanks if there is the slightest chance of water boiling anywhere in the system.
> I read the postings here regularly and have a few >welding/fabrication questions.
> I'm installing a wood fired boiler in my home and >need a hot water storage tank. Something around >500 gal and sized for entry through a standard doorway. >That precludes a propane or other such type tank.
> It has occured to me that maybe the local welding shop >could fabricate such a tank but I am aware that there >are issues with a rectangular pressue tank even though >is operates at a low pressure of 10-12 psi's.
> Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' >in size mild steel. Bent corners, flat ends, closely spaced >internal baffles/exterior bracing?
>Hydro test to 1.5 operating pressure.
>Any thoughts appreciated. ED
I suggest that the question is whether this tank is a pressure vessel or not?
I know that you mention 10 - 12 PSI but where does that number come from? It is hardly sufficient to use for a household pressure water system. Are you perhaps thinking of the pressure exerted by the head of water inside the tank?
If the latter then it is not a "pressure vessel", as the term is normally used, and there shouldn't be any problem in building a rectangular tank.
In fact I'm sitting in a shipyard looking at several fuel tanks, temporally removed from a trawler, of the size you mention, welded up from mild steel plate, that have probably been in use for 5 - 6 years with no problems.
Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)
<decypher_signat...@signature.line> wrote: >On Mon, 30 Jun 2008 07:31:10 -0600, ED <albieguyspaml...@yahoo.com> >wrote:
>> I read the postings here regularly and have a few >>welding/fabrication questions.
>> I'm installing a wood fired boiler in my home and >>need a hot water storage tank. Something around >>500 gal and sized for entry through a standard doorway. >>That precludes a propane or other such type tank.
>> It has occured to me that maybe the local welding shop >>could fabricate such a tank but I am aware that there >>are issues with a rectangular pressue tank even though >>is operates at a low pressure of 10-12 psi's.
>> Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' >>in size mild steel. Bent corners, flat ends, closely spaced >>internal baffles/exterior bracing?
>>Hydro test to 1.5 operating pressure.
>>Any thoughts appreciated. ED
>I suggest that the question is whether this tank is a pressure vessel >or not?
It is for a hydronic hot water heating system, average operating pressure of 10-12 psi but could go as high as 30 psi in some circumstances.
>I know that you mention 10 - 12 PSI but where does that number come >from? It is hardly sufficient to use for a household pressure water >system. Are you perhaps thinking of the pressure exerted by the head >of water inside the tank?
There are circulation pumps in the system along with heat loads and the general head of two stories.
>If the latter then it is not a "pressure vessel", as the term is >normally used, and there shouldn't be any problem in building a >rectangular tank.
>In fact I'm sitting in a shipyard looking at several fuel tanks, >temporally removed from a trawler, of the size you mention, welded up >from mild steel plate, that have probably been in use for 5 - 6 years >with no problems.
Thats what I was thinking of when I posted this question How do you think they would handle the forces of 15 psi?
>On Tue, 01 Jul 2008 14:53:25 +0700, Bruce in Bangkok ><decypher_signat...@signature.line> wrote:
>>On Mon, 30 Jun 2008 07:31:10 -0600, ED <albieguyspaml...@yahoo.com> >>wrote:
>>> I read the postings here regularly and have a few >>>welding/fabrication questions.
>>> I'm installing a wood fired boiler in my home and >>>need a hot water storage tank. Something around >>>500 gal and sized for entry through a standard doorway. >>>That precludes a propane or other such type tank.
>>> It has occured to me that maybe the local welding shop >>>could fabricate such a tank but I am aware that there >>>are issues with a rectangular pressue tank even though >>>is operates at a low pressure of 10-12 psi's.
>>> Would it be adviseabel to try such a thing? 12 ga 5'x6'x2.5' >>>in size mild steel. Bent corners, flat ends, closely spaced >>>internal baffles/exterior bracing?
>>>Hydro test to 1.5 operating pressure.
>>>Any thoughts appreciated. ED
>>I suggest that the question is whether this tank is a pressure vessel >>or not?
> It is for a hydronic hot water heating system, average operating >pressure of 10-12 psi but could go as high as 30 psi in >some circumstances.
Sorry, never heard of a "hydronic" heating system. Is that a thermal syphon system?
I've seen hot water heating systems in New England, called Base Board Heating because the radiators were located close to the floor, and they did not use a pressurized reservoir.
>>I know that you mention 10 - 12 PSI but where does that number come >>from? It is hardly sufficient to use for a household pressure water >>system. Are you perhaps thinking of the pressure exerted by the head >>of water inside the tank?
>There are circulation pumps in the system along with heat loads >and the general head of two stories.
I hesitate to comment as I am not sure how you have the system designed but what is the advantage in pressurizing the reservoir? It would seem simpler to heat the vented reservoir and pump the heated water through the system.
>>If the latter then it is not a "pressure vessel", as the term is >>normally used, and there shouldn't be any problem in building a >>rectangular tank.
>>In fact I'm sitting in a shipyard looking at several fuel tanks, >>temporally removed from a trawler, of the size you mention, welded up >>from mild steel plate, that have probably been in use for 5 - 6 years >>with no problems.
>Thats what I was thinking of when I posted this question > How do you think they would handle the forces of 15 psi? >> ED
When you mention 15 PSI and then say that pressure might go to 30 PSI you are talking about a 100% increase in pressure.
Certainly you can design a rectangular vessel to hold 30 PSI but it will probably either be made out of thicker gauge then necessary or internally braced to prevent the flat sides from dish panning.
>>Bruce-in-Bangkok >>(correct Address is bpaige125atgmaildotcom)
Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)
