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Johnny Longprong

Great, insect protection is important and Borax will help there. My experience with cane is that you need to provide protection from the elements most of all, particularly sun if you want it to last.
Wouldn't you be better soaking the tubes in a bath, or are you expecting that the pressure will push the solution through the node barriers? Sounds though that you have thought this through and I really have no idea about stuff all, but am interested in your project.

More Volts Igor

He's aiming for a High Pressure Sap Displacement system, replaces the sap in freshly felled stems with a preservative. A bit like embalming a body where the blood is replaced with embalming fluid.

Smithson

That's it, this allows the bamboo to be treated much faster than soaking it.

Still having no luck with the tank. The fire extinguisher will probably work, the important thing is that it will pump the solution, rather than air, into the bamboo.

blackgang

If you have liquid in the tank, and the outlet is at the lowest part of the tank, there is no way that anything but liquid will be expelled from the tank.

Smithson

Yes, but where do you get such a tank? The fire extinguisher has a tube running to the bottom

watterinja

A simple & safe way would be to design a series of parallel, small diameter tanks, made from schedule pipe. This has a very high burst pressure. Add schedule end-caps & piping nipples - weld end-caps to pipe section.

Go out & chat to a local pipe-fabricator. In the west, these are easy to find - not so sure about Thailand.

Smithson

Sounds tricky to me, especially the bit about talking to the pipe fabricator. Most of these ppl didn't study their trade, take a look at the welders.

blackgang

Like I said before, Go and buy a used air compressor, or a new one if you want, but one with a large enough air receiver to do your job, put your discharge fitting in the bottom, say in the place where the water drain is located, fill as full of product as you want, set the compressor shut off switch to the pressure that you need on your product and start it up and all automatic til you need to refill with your chosen liquid.

Then when you are finished with your experiment you will have an air compressor that is still useful as an air compressor.

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lom

Why don't do just that , pump air into the bamboo?
Should work if you have filled the bamboo with borax solution.

Smithson

Interesting idea, but not sure if it would work. A fair bit of solution is required. The tank system allows many poles to be done at once.

Smithson

Thanks for the advice, I've found a place selling old fire extinguishers and there's info on the net for converting them, although not for liquids, it's still helpful.

Once it's drained, is this 100% that there is no pressure in the tank? I'd hate to get it wrong.

Thetyim

^
Mine was a dry powder filled one.
After the kids had sent it off there was no pressure left in it but a load of powder so open and clean it outside.

Smithson

It looks like the extinguisher won't be able to hold enough liquid. I'm now considering the tanks that are used on water pumps. According to the info on side of the tank, they are capable of holding pressure up to 4 bar.

I've found a stainless steel one that holds about 25 liters, hopefully this will do the job, the poles I'm treating are 9 meters long.

Happyman

Alternative source would be a scrap yard and look for a brake cylinder from a truck

Smithson

Back home it'd be worthwhile, but my mrs has a saying, "2nd hand more expensive than new". Second hand crap that is thrown away at home is selling for 80% of the price of the new things.

blackgang

Must mean an air receiver from a truck with air brakes, but that would not be of a size to do what you want either.
And yes, a water pressure tank from a well pump would do you just fine, just do not exceed the pressure stated on the tank.

Smithson

Thanks for the help, everything is ready, except I need a filter. This will be placed between the tank and the splitor. The idea is to catch suspended particles within the solution, as these will block the ends of the bamboo.

Any suggestions for making a suitable filter? 2" PVC pressure pipe would be suitable, however I'm not sure what material to fill it with. I needs to filter fine particles without reducing the pressure. Any ideas?

baldrick

any obstruction is going to cause a pressure drop , even straight pipe causes a pressure drop over length.
a good idea will be guages at both ends of your filter so you can accurately work out what pressure you are injecting at. it will also tell you when the filter needs to be cleaned.

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Smithson

This is correct, actually it's difficult to see how a filter would work, it would either cause major pressure drop or the pressure would push than suspended particles thru.

baldrick

normally in industry you will have across the filter - and normally 2 filters - allowing for bypass , isolation and removal.

basic - a dial pressure gauge at input and output
normal - a differential pressure switch which will toggle an alarm when the diff pressure setting is reached.
good - A diff press transmitter to the DCS which allows a trend log and also alarm , shutdown switches , this will also have guages and a diff press switch as separate backup.