Re[2]: Certification of Type A Packages

[forrere@ccmail.orst.edu]

          This may seem like a very basic question, but, what would
          the difference be between putting a container inside a
          chamber and dropping the pressure or putting a valve on the
          container and increasing the pressure inside.  It seems to
          me the test is to determine if the container can withstand a
          certain pressure differential not necessarily a specific
          internal reduced pressure.  Correct me if I am wrong, and I
          often am, but won't a pressure differential of ten pounds
          (random number) have the same effect whether you have
          atmospheric pressure on the outside and an increased
          pressure on the inside or atmospheric on the inside and some
          reduced pressure on the outside.  I thought that a good way
          to test steel drums would be to install an automotive wheel
          stem valve on the lid and pressurize it.  You could easily
          check the pressure and monitor any decreases in the
          pressure.  Has, can and should it be tried?  Why?  Why not?

          Gene Forrer