Well , well , I had post my question , in what I touhgt it was the simple way to do it .
Guess a horizontal pipe lying on a flat lake , one or both end are conected to the atmosphere.
I never guess that this question would make a so interesting discussion.
Now I will change my question.
I need to do a chamber with a 40" lenght pipe, the same pipe section diameter and material.
Both end caps are flat plates , tick enough to not to be in cosideration , guess 4" or more what ever is need .
The caps have a small grove and an "o" ring to seal it .
The caps are have 4 threaded bar to join it with the pipe, of course 8 nuts do the final job.
Like a old way of air filter.
Or as the caps where blind flange and the pipe a 40 inch length gasket , all arrange with the belonging stud or bolts and nuts.
All the array is vertical stand.
The atmosphere is normal or about 28.79174 inch Hg
The temperature is ambient
Now the final question , how low I can make vacuum inside the chamber????
Hope it does make a new and nice discussion , as the previous.
