I'm glad I succeeded in putting across the difference between both pump mechanical designs. I didn't devote much time to the sketches due to work load, and I apologize for that.
I sense a real interest on your part in determining what are the main positive/negative characteristics or tradeoffs between the two basic designs. And I would encourage you (& all other engineers) to always think along these lines when selecting, applying, and operating centrifugal pumps. There are major mechanical differences between models or types, and these differences can sometimes determine the relative success or failure of an application. Therefore, I consider it vitally important for all chemical engineers to become totally immersed in the mechanical design and features of centrifugal pumps because the wrong pump type in an application can cause operational and maintenance problems, expenses, inefficiencies, and much grief. Some chemical engineers involved only in the design phase of engineering pay little or no attention to these factors - and that is not only a shame, but in some cases it constitutes neglect and professional deficiency. Those of us who have been in operations and production disciplines know full well how important it is to select and apply the correct pump type to a process.
We could spend a lot of useful, profitable time discussing the pros and cons of all the different models and pump types, but I will leave that subject to another thread and another time - for now.
I am glad you found the Goulds website profitable.There is a virtual gold mine of information there if you take the time to read it and follow it through.