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I'm sure there is a simple answer here, so I apologize in advance for the unchallanging & low level question, but here it is:

 Why does the water at water oulets, through out a building, stop their water flow near instantly when the Rising Stem Gate valve at the out side water main is shut closed, But will trickle and trickle with little flow for almost an hour when the indoor building main ball valve, downstream of RSG valve, is shut closed.

Building has 3 floors.

Anything helps.

enter image description here

DKNguyen
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Max R.
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  • It seems like you are really asking if there is some difference between how the two different values close. I assume that both valves are in relatively the same location. Is that all correct? – hazzey Mar 31 '19 at 19:35
  • Maybe. I mean what else am i to think when i get different fluid behaviour after shutting off 2 different style valves. Yes, that is correct. – Max R. Apr 02 '19 at 21:24
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    Why is your photo not rotated correctly? – Transistor Aug 23 '20 at 22:04
  • @Transistor. Sorry, this was some time ago and I posted it up in kind of a hurry due to the problem I was coming across at that time. I don't know if there is a way to change its orientation from the web site, and I don't know that I have that photo anymore. I wish I could edit it *sad face*. – Max R. Aug 25 '20 at 22:19
  • maybe smth to do with elevation? imagine pipes full of water, supply shut off at ground level. Lets say faucets open on only on the 2nd and 3rd floor. Water in pipes can flow from 3rd floor down to 2nd floor. It would look like flow stopped on 3rd floor but not 2nd, I think. Now repeat with faucet open on 1st floor too. It will look like flow stopped on 2nd and 3rd floor... – Pete W Jan 21 '21 at 01:10
  • ... so when shut off at mains, some equipment below ground level is acting like open faucet to absorb the flow from the pressure of outlets above, creating the backwards flow that makes it look like "instant stop" ??? when shut off at ball valve, that equipment is cut off, and everything drains to the next outlet that is higher than the shut off point (?) just speculating – Pete W Jan 21 '21 at 01:11

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Valves tend to leak, the amount depends on the design, size , seat materials, condition/age of the valve, pressure , and probably things I missed. So it would be difficult to guess the specific problem . Because of these factors , refineries use two valves in series for critical lines even though they get "good" valves and ( sometimes) verify construction quality. And well head valves are leak tight when new; however, a 3 -9/16 " ( standard size ) well head valve can weigh 5,000 lb ( for a 15,000 psi rating), ( I have no idea what the price is now).

blacksmith37
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  • Uhm, well, sure maybe. I never thought that would be the case considering the size of these valves and their pipes. – Max R. Apr 02 '19 at 21:28