Shelby Tube Permeameter

[geomane]

Do any of you have experience using a Shelby Tube Permeameter? I am looking into purchasing one to compare test results with my current laboratory permeability testing methods.

The permeameter I am looking at can be seen in the link below:

http://www.globalgilson.com/productdisplay.asp?group=ShelbyTubePermeameter

My question is in testing a 3"x6" shelby tube. Can you purchase a shelby tube with those dimensions? Or, do you cut the shelby tube? If you cut it, do you use a pipe cutter or band saw? I would rather not have to cut it, because you are then further disturbing your 'undisturbed' sample.

Thanks for any responses.

 

[oldestguy]

INTERESTNG QUESTION. I've run many a consolidation type test with peat samples left in a 3" diam. Shelby tube. This avoids handling the sample and, hopefully, represents undisturbed material. That was with a home-made loading apparatus, suitable for significant compression. Tubes were cut off with a band saw and a porous filter stone of the correct diameter placed in each end. Length of tubes varied between 5 and 12 inches, depending on what the material was.

For what you want, you probably can make up a set-up say with the base of a Proctor mold or similar lower support fitted with a suitable stone inside both tube ends, but use the two hold down threaded rods to clamp a cover on top. A gasket is needed at the top of the tube. Some form of drain is needed in the bottom and you might place a measuring container there also. Then run a clear plastic tube or similar up from a hole in that cover. You can get what ever head you want by a sufficient length of tubing and in a room or area where that head room is available. I've run these tests in stairways to get a big head. Knowing the tube inner diameter you an calculate flow and thus permeability.

This sort of testing can work, especially for unusual materials, such as peat, bark, foundry sand, etc. where conventional methods are not very suitble.

 

[MEM1]

I am assuming you are not using a flexible wall permeameter. The testing we do ASTM D5048 is the flexible wall type. There was an engineer around here that used to use a different method, not sure which standard, but I believe he was cutting the Shelby tubes and placing the porous stone on top of that. Not sure how he was cutting. Sorry, I'm not much help.

 

[geomane]

Yes, this is a flexible wall permeameter.

 

[bb29510]

you can buy a 12 inch shelby tube, then take a sample auger and trim to desire length. The auger is not the correct term but i don't know what its called. t handle fit inside shelby tube to square the sample

 

[fattdad]

In the absence of a membrane, cell pressure and backpressure, you'll have uncertain boundary conditions. There is no way to guarantee saturation.

f-d

ípapß gordo ainÆt no madre flaca!

 

[geomane]

Rigid-wall permeameter. I meant rigid-wall permeameter.