My understanding of the CSV is it stops the pump from cycling (turning on-off-on) during specific usage situations where the usage (draw down) flow duration is longer than the normal pump cycle duration. Thus it stops the pump from turning off/on several times when water is constantly being drawn. Which is good.
(IMHO) Depending on your ballast tank size, for most usage like flushing a toilet, brushing your teeth, washing hands, filling a pan of water, the short duration of your draw doesn't cause your pump to repeatedly cycle and I don't see the benefit of a CSV.
Don't get me wrong, there's long duration draw down applications where a CSV makes sense, but it does sometimes seem like its promoted here by its inventor as a solution to any post regarding well pumps. That's my impression.
I don't have a problem with Valveman, his forum name lets you know where here's coming from.
It does remind me of being at a horse once show with my wife watching our daughter ride. A nice lady next to me started talking about how nervous she was watching her daughter...we were nervous too...a pretty lady, a nice friendly conversation, then she mentioned the thing that calmed her nerves was Lavender Essential Oils. How they made her sleep well, gave her focus, relieved soreness (might of cured cancer too!)..okay...that's interesting...blah blah blah...and then she just happened to have some extra bottles for sale...."and oh by the way......what's your email so I can get you on the mailing list for the whole product line of Essential Oils." or maybe she gave us a business card with the weblink.
Then I thought to myself "Oh, that's what this "friendly conversation" is about...ok, uh-huh"
The whole encounter felt.....what's the word?