Gabe, the water absorption rates I posted for the various Tygon tubing were done by this standard, according to their .pdf files of the various tubings I listed from Saint-Gobain's website:

ATSM D570 for the Tygon Silver, Tygon B-44-4X, Tygon F-4040

ATSM D570-81 for the Tygon LFL,

ATSM D570-98 for the Tygon R3603


So, I think the water absorption, as Saint-Gobain put it in their .pdf's, is indeed the same values you want to know as the permeation rate, or the Water Vapor Transmission Rate......

Now, I do not know what the difference between just ATSM D570, D570-81, and D570-98 are.....maybe you could fill us in?

You mention vacuum resistance......the same .pdf's, again available on Saint-Gobain's website in each tubing's description page, lists these properties for different tubing....


Tygon R-3603....... in 3/8" ID X 5/8" OD..... 29.9" of mercury at 73F.

Smaller tube thicknesses in the 3/8" ID range are lower.




Tygon R-3603 with 7/16" ID X 5/8" OD ...... 15" of mercury at 73F.

7/16" X 11/16" OD ........... 28" of mercury at 73F.



Tygon R-3603 with 1/2" ID X 5/8" OD ..... 5" of mercury at 73F.

1/2" ID X 3/4" OD ...... 21" of mercury at 73F.




Link to Tygon R-3603 specs webpage w/.pdf link for testing specs, measurements, etc.

Link to webpage of all Tygon tubing....lots of interesting variations in Tygon.