Re: Re[2]: Certification of Type A Packages

["William A. Fendt" <35346@strauss.udel.edu>]

It seems to me that a container may be structurally engineered to 
withstand crushing forces instead of expansion forces or visa versa.

On Wed, 29 Jun 1994 forrere@ccmail.orst.edu wrote:

> 
>           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
>