Thanks guys. My new word for the day is "confirmation bias". This describes why so many people get angry with me when I tell them the big tank they just bought or the VFD they got talked into are not the best ways to control a pump. They already made up their minds, bought the big tank, and just come to the forum because they want confirmation they did the right thing. Then they blow a gasket when I tell them big pressure tanks are no longer the best way to control a pump. Lol! At least in this case you have not yet purchased the big tank. But you are still wanting confirmation that it is the best solution, and I have too much experience on the matter to agree with that.
In the past a huge pressure tank was always the best way to control a pump. There are only a few problems with using a large pressure tank, and the Cycle Stop Valve solves all of those. Space and cost are the most obvious savings for using a CSV and smaller tank. A larger pressure tank also causes the wide variance in pressure to be more prolonged. With a 50/70 pressure switch the pressure is good and strong for a short minute as the pump quickly fills the tank to 70 and is shut off. Then the pressure gradually gets worse and seems to linger at the low side of 50 PSI for a long time before the pump is restarted. The pump/motor running at full amperage and making max heat only runs for one or two minutes to fill the tank. Short run times trap heat inside the motor, which cannot be dissipated in such a short run. Then because the pump cycles on and off while you are using water, it doesn't have time to properly cool down before the next start. Starting a hot pump/motor is just as bad as trying to start a car engine immediately after it has shut down from overheating. There is also water hammer that happens when a pump fills a tank at max flow and then quickly shuts down, as the check valve slams shut from the wide open position. Drawing max flow for a minute then shutting off while the pump cycles on and off repeatedly also surges the well up and down, stirring up sediment and other contaminants.
Adding a Cycle Stop Valve to the old and fairly dependable pressure tank system solves all those problems and more. The CSV works with a smaller and less expensive pressure tank. The CSV holds the pressure strong and constant for the duration of showers and other long term uses of water. The smaller tank causes the annoying drop in pressure from 70 to 50 to be quick and basically unnoticeable. The CSV causes the motor to run cooler at lower amperage and run long enough to dissipate what heat is generated. Since the CSV does not let the pump shut off for a minute or two AFTER all water taps are closed, the pump stays off long enough to properly cool down before starting again. The CSV only fills the pressure tank at 1 GPM, which means the check valve is almost closed before the pump shuts off. This eliminates water hammer and the destruction it causes. The CSV steadily draws only as much water from the well as you are using, which prevents the water level in the well from surging up and down stirring up contaminants and sediment.
Then as I said, the CSV is a show me type of thing. The suggestion that 100 small uses of water a day would cause 100 cycles is incorrect. If the 2.5 gallons in the 10 gallon size tank is enough to supply several small uses before the pump is started. Then once the pump does start, the CSV keeps the pump running for as long as water is being used, then keeps it running for an extra minute as well. During that minute if more water is used, the pump just stays on for those uses as well, then ANOTHER minute as well. The gallon or two supplied by the small pressure tank plus the mechanical timer of filling the tank at 1 GPM turns 100 small uses a day into maybe 20 pump cycles. When any of these small uses happen at the same time as someone else in the house is taking a shower or using water, they do not add to the number of cycles.
This is all assuming you do not have any irrigation, use a sprinkler for anything, the kids don't play with the garden hose for hours, or you have a leak you don't know about. Any of those things will cycle a pump to death without a Cycle Stop Valve, but would be absolutely no problem at all for the pump if you have a Cycle Stop Valve.
It is impossible to do the math when you have no idea how people will use water during the day, nor can you plan for unintended uses of water like a hose left open or a leak. You also cannot do the math without understanding the mechanical timer thing. Basically the CSV solves all the problems associated with the old pressure tank method, cost less, saves space, and delivers much stronger constant pressure to the showers and appliances.
Water does not come from the pressure tank, it comes from the well and pump. A pressure tanks only purpose is to limit the on/off cycling of the pump, and when you have a CSV to do that, you don't need much of a tank.
But if you had rather spend a few hundred bucks extra, a big tank will take up more space in the house, have varying pressure at the showers, cause water hammer, surge the well, and shorten the life of the pump and system. I would never say "just trust me". I have done the math everyway it can be done, and have experience from over 50 years and hundreds of thousands of pump systems installed. With over 30 years of selling Cycle Stop Valves I have thousands of references, or reviews they call them now, from customers who prove I got the math right and know what I am talking about when I say the Cycle Stop Valve is superior to any other pump control on the market. I have even further proof of this from being blacklisted by all the pump manufacturers back in 1994 because, and I quote, "The CSV is a disruptive product making pumps last longer and using smaller tanks. Any employee who mentions a Cycle Stop Valve will be terminated immediately".
You maybe "data-driven", but unless you really understand pumps, which very few people do, you just do not understand the data that you have been given. The CSV is only a $89-$200 valve. I have gone to a lot of work to explain the data to you. You don't have to get a CSV now. You can add one later when the wife starts complaining about low pressure in the shower, the water hammer is driving her crazy, or the kids left a garden hose running and cycled the pump to death. $200 worth of prevention could be prevent thousands of dollars spent on a cure. But using "confirmation bias" you can convince yourself that a big tank is the best solution.
