Well pressure tank: Does well-side supply line pressure match tank pressure?

[ponytug]

Yep. With a flowing stream they work quite well. Low output but it is outputting 24/7 so...drawback is hardly any pressure at point of use. There are homebuilt one using nothing but pipe fittings. Neighbor had one feeding his house (50 gal barrel in kitchen) Pump was almost severy hundred yards away.

The pressure isn't necessarily low, as the output pressure can be "tuned" by how you set the check valve in it. An older relative had one a spring near the house that he ran at 100-110psi. The house had amazing pressure, but was a little prone to springing random leaks...

I'm not sure why he ran it so high.

Here's a video of a commercial ram running at 156psi or so. (110m of water height)

Many of the "free" designs for a water ram pump are actually quite inefficient as many people seem not to understand that water hammer benefits from a long straight run directly at the check valve. The one in the video above has a large radius sweep that helps.

All the best,

Peter

 

[SPYDERLK]

Talk about ConFusion!
Liquid flow has parameters that are independent of system size. It is all about the change in liquid velocity.

I would be better to address the quoted post rather than misrepresent it by fixation on a single word in it.

 

[Valveman]

I think I am being full bore insulted. Lol! The physics of a "backyard water system" is exactly the same as a large scale system. The engineers who were squirted out of the manhole would also disagree with "virtually every design and operation choice has been poor". It was a highly engineered municipal water system, they simple turned the speed control knob on the control valve the wrong way.

The "real phenomenon" that happens in large scale water systems is the same as in small scale water system. Is is just that when a transient pressure wave is traveling at 3K to 8K feet per second, a 7 mile long 8" pipe line makes it take several seconds for the wave to go from one end to the other. I have had the benefit of being able to watch the pressure gauge bounce from one extreme to the other, over and over again. And this happens for several minutes before is subsides. In a back yard water system the exact same thing happens, but in 70' of 1" pipe it happens in a millisecond and you just can't see it. The same water hammer spike that squirted two engineers out of a manhole on the large system will cause broken fittings, splits in the pipe, and failed components such as check valves in any size water system.

But it is very confusing. Manufacturers of check valves will suggest installing one every 200'. Lol! Control valve engineers would know this can cause major problems and recommend against multiple check valves in a line.

 

[repete]

I am late to the party here but if your well pump can pump say 25 GPM and your well is only capable of 10 GPM flow, somewhere in that line you have a restrictor so that you cannot receive the full 25 GPM and cavitate your pump.
If that flow restrictor is at the pressure tank you have the potential of higher pressures on the pump side of the restrictor than at the tank itself. If it is a 10 GPM well and you have a 7 GPM sprinkler running on the "house" side of the pressure tank and you place another 7 GPM sprinkler on the line before the flow restrictor, you will be asking the 10 GPM well to supply 14 GPM. This may cause you an issue.

 

[SPYDERLK]

I think I am being full bore insulted. Lol! The physics of a "backyard water system" is exactly the same as a large scale system. The engineers who were squirted out of the manhole would also disagree with "virtually every design and operation choice has been poor". It was a highly engineered municipal water system, they simple turned the speed control knob on the control valve the wrong way.

The "real phenomenon" that happens in large scale water systems is the same as in small scale water system. Is is just that when a transient pressure wave is traveling at 3K to 8K feet per second, a 7 mile long 8" pipe line makes it take several seconds for the wave to go from one end to the other. I have had the benefit of being able to watch the pressure gauge bounce from one extreme to the other, over and over again. And this happens for several minutes before is subsides. In a back yard water system the exact same thing happens, but in 70' of 1" pipe it happens in a millisecond and you just can't see it. The same water hammer spike that squirted two engineers out of a manhole on the large system will cause broken fittings, splits in the pipe, and failed components such as check valves in any size water system.

But it is very confusing. Manufacturers of check valves will suggest installing one every 200'. Lol! Control valve engineers would know this can cause major problems and recommend against multiple check valves in a line.

Yes the Physics is the same, and so in any formal analysis would cover all the variables of size and choice. The increased risk of a large system is essentially inherent in its size, construction, and purpose. Move a lot of water a long way fast in high modulus pipe. What would Physics say?; control pumps for soft start/stop, use pipe of low elastic modulus, control valves for gradual Open/Close transition, build in some surge volume to forgive any failing of graceful flow control.

A backyard water system typically uses a deeply submerged fractional HP centrifugal pump with a soft close check, 10 GPM max flow, low modulus (poly plastic) piping, a surge tank close to the source and another at the end of the line if "distant", and slow valving relative to the short distances involved. Stay away from solenoid valves and youve just got water nerf.

Yes, some are easily confused. They are prone to take a real phenomenon, awesome in its effect in large scale systems where virtually every design and operation choice has been poor, and then sensationally apply such effect, full bore with negligent regard for operating nuances and convenient moderating choices, to a guys backyard water system.

 

[Valveman]

Submersibles use a standard check valve, nothing soft close about them. But even silent or slow closing check valves cause water hammer when the pump shuts off while pumping max flow, even just 10 GPM pumps. It is also impossible to stay away from solenoid valves if you have irrigation or a heat pump. Like you said, "the physics is the same". So the same water hammer in large systems happens in small systems, just to a lesser degree and harder to see. I still don't know what "water nerf" is. But if it will stop water hammer on a domestic size pump system I want one.