[erase42]

LOL, cmon guys play nice. Its not that anyone is right or wrong, its just a matter of physics. Some people just haven't heard all of the laws yet so its a lot easier to do stuff like this. I for example have not read up on any sort of engineering or structural design yet which is enabling me to build the new second story of my house entirely out of used starbucks cups and twist ties. Ill send pics when its done.

[ratsarsed]

Every one seems to forget that the 9" sq tubing works for this guy.. That means all he
needs to do is treat the wood while it is still curled up from his veneer lathe,
before gluing it into sheets.

Cheers
--
Use a rotary telephone and never need to Press # 1 to Speak English

[unterhaus]

Every one seems to forget that the 9" sq tubing works for this guy.. That means all he
needs to do is treat the wood while it is still curled up from his veneer lathe,
before gluing it into sheets.

If he can do it while it's rolled up, he can use a round tube, which is far superior. I have seen square pressure vessels, and they require a lot more space and material because they have big flanges on the outside to keep the shape of the vessel. Furthermore, a 13 inch ID pipe is going to be far, far cheaper than the heavy wall 9" square tube he's going to need for the same square interior space.

[calthaus]

The rectangular design should be avoided. Any cylindrical pressure vessel is going to be much more efficient in material usage and in strength. You probably are better off building multiple tanks out of say sch. 40 pipe. Or just buy a used air compressor and strip the pump off and use the tank. What ever you do just remember that pressure vessels are designed with a safety factor of >10 for a reason. They hold a huge amount of energy.

[huckster06]

... Tank mfgrs. use special grades of steel that rip slowly not fail catastrophically-don't know the grade. ...

It is true that there are special grades of steel designed for pressure vessel construction. However, just using the correct grade does not guarantee that failure will not occur. Well designed pressure vessels will use a leak-before-break design strategy so that the probability of catastrophic failure is reduced. To perform a leak-before-break analysis one also needs to understand fracture mechanics as this is an integral part of the analysis. The problem with square pressure vessels is that the stress concentrations at the corners becomes incredibly high. Thats the reason all pressure vessels are cylindrical or spherical as this shape equally distributes the stress throughout the material. Even cylindrical pressure vessels can be tricky to safely design as the inclusion of holes or bungs causes large stress concentrations. It's a free country but I would discourage you from attempting any kind of pressure vessel design or fabrication, square or round.
In case you still want to tempt fate check out some equations for hoop stress and axial stress. There are separate hoop stress equations for thick or thin walled vessels and separate equations for flat ends or spherical ends. Oh, and there are NONE for square pressure vessels. Guess why.

[Zumba]

Congrats, Huckster. You are 3 months late in answering... :rainfro:

[Nzoldun]

At that size and pressure, I can guarantee that your unit would be a (legal) pressure vessel and would have to meet statutory requirements.

I'm not absolutely sure, particularly in regards to actual requirements, state to state, in the US, but am 99 % sure you would need to comply with ASME VIII.

I routinely use it for the design of vessels and exchangers for the Petrochem industry, here in New Zealand - although nothing like the scale of the US!

[paul3112]

mmmmm boooooommmmmmm try a pump http://www.catpumps.com/pump-selecto...ifications.cfm

Just a thought