Can’t tell you how pleased I am to hear that!

@@ProcesswithPat I've been a process engineer for ~16 years. Whilst I understand all the concepts you explain, I can see how learning these at an earlier stage in my career would have been invaluable. Keep up the good work.

@@ProcesswithPat It's a great video but it can be even better :) In terms of pressure (& neglecting friction losses as you correctly indicated) they are equivalent.. but let me add an important note to your very helpful video: There is a major difference when the pump stops... the water will come back in cases B & C... this means that the pump will turn in the opposite direction which will prevent you from running it again & possibly damage mechanical seals (if used) & other critical pump components... Neglecting the extra cost, You can put an NRV (non-return valve) but what if it passes water? Or requires maintenance? Yes you can put an isolation valve... but this is not the correct way... you should select the inherently stable system; that is case A (Unless the system is small, You will have to put both the mentioned valves in case anything happens in the middle! But you will not have to worry about the water in the tank only the water in the line) *having taught students for a long time I learned that I have to mention such significant points or at least "stress" on the fact that the comparison is strictly in terms of a specific aspect (in this case; pressure/head only) & in reality many other aspects have to be considered... this is because many would have the tendency to "over simplify" the problem, just repeat that everything is equivalent & cause a disaster! * again I know it is not directly related to the question but yet I feel it is important to mention such issues, have a good day

Nicely articulated, one could say "case study in over simplification" by focusing on pressure alone. In my own 13,000 litre heat in water solar capture system, the fill line is small diameter Flexi, providing a low continuous rate of circulation of warmed or chilled water through any one of 13 containers with filling at any level adjustable without valves by manually physically relocating both the flow and return lines without disconnection of a pond pump directly attached at the inlet and a solar panel providing flow in proportion to incident heat. Any the high pressure generated and friction in long lines is accepted as free heat making the inefficiency of overpressure into a benefit. A loss into a gain.

@jmohammedtt ...and for really old guys like me that have forgotten so much of this kind of thing!

True, but one advantage of filling from the bottom is there is less head pressure during the entire filling processes, only when the tank is full is the pressure the same as filling it from the top.

That potential problem could be prevented by putting a check valve in the line right after the pump.

@@actionjksn It can be, though there is a pressure drop across that valve too, although an active valve (pneumatic for example) could reduce that to almost nothing. Like anything in engineering there are multiple solutions.

@@justanotheryoutube ... while that makes perfect sense, the main reason to fill from the top has to do with fluid dynamics where an open ended pipe just has less restriction and an even flow rate throughout the fill process. BTW, the open end also acts as a siphon breaker in the event of needing pump service. IOW, you don't have to empty the tank.

@justanotheryoutube and @rupe53 The other reason to fill from the top of the tank is that the Pump is pumping against a known and constant head. If pumping into the base of the tank and the tank having varying fluid levels, the Pump is not pumping against a constant value but a value which varys with the level. Pumps have an head curve where there typically is a narrow range of optimal conditions. Pumping to the top of the tank removes one of the variables in the design.

When I pump horizontal, how do I know how long my pipe can be? I want to pump water 100 - 200m through the garden (downslope) in pipes that maintain some pressure for the sprinklers. I understand this height (Hm) now a bit, bit i haven't figured out how to calculate how strong my pump needs to be to keep pressure for 100 metres of pipe. Can anyone explain?

But in case A there's always a maximum counter pressure even if the tank only half full. This will reduce the flow quantity.

"not directly related to the question" Wrong, I suspect an extreme case of modesty 😀 But seriously, some mention of application is both helpful in sustaining interest AND understanding the theory.

@@gr8dvd Thanks Indeed, Slowly Injecting things from an application perspective will always help fresh engineers/students (we can not go full throttle on details since it will deviate us from the topic at hand, but "some mention of application"👌 is much better than the "bone dry Theory" methodology)

@@JaakJacobus *I did not understand what you mean by "counter pressure" *In Case A, the tank is filled from the top not the bottom *If we are talking about the same case, do you mean the friction losses/head losses (which translate to pressure losses) due to the length of the pipe & fittings? In cases B & C, The entrance losses are very large especially if it is directly from under the tank as shown (rather than from the lower level but from the side of the tank)... this is due to the induced turbulence in the tank at the entrance * even if the losses are larger in case A (which is unlikely), the huge disadvantages of the other cases (mentioned in my previous comment) force us to use case A in practice * the drain of the system should be at a low level & on the side of the tank... not the entrance This is Another reason why we don't put the entrance below... since all debris, rubbish, sand, gravel...etc tend to go down such openings and choke the pipe (causing interruptions in operation & resulting in expensive repairs...) * extra: Some times, especially in large size pipes we use "long neck" elbows to reduce the friction losses caused by traditional elbows (due the abrupt change in flow direction) When filling the tank, in small systems we usually use "floats" to signal the pump/s to stop once the water reaches a certain level (which should be below the entrance level) In bigger scale systems we usually use other means such as ultra-sonic sensors to stop the pumps... Hope this helps :)

Another reason why we don't put the entrance below... since all debris, rubbish, sand, gravel...etc tend to go down such openings and choke the pipe (causing interruptions in operation & resulting in expensive repairs...)

It reduce the quantity of gas in the liquid too, wich greatly reduce cavitation in the pump. This why even if you pump in the top of the tank often the pipe continu in the tank to the bottom. Essential in case of high pressure pumping.

my tank fill at the top, or otherwise the water will run back to the source when source has no water....... or check valve is needed

@@theeraphatsunthornwit6266 You have the most reliable check valve possible.

True. When refueling aircraft they pump from the bottom of the wing for a couple of reasons. They don't have to pump a greater amount of fuel up and over the wing. Also, it's safer than having to drag the hoses over the wing and even possibly damaging the wing.

Not only that, ik you fill from the top, like in the example as seen in the video, you ALWAYS have to rise the water 3 meters, and the pump always has to use maximum presure ( and energie) to do that. when filling an empty tank from the bottom, it just costs a lot les energie to do it from the bottom. than from a fixed heigth at the top.

But pumping to the top of the tank results in a constant pressure, allowing you to design a pump for that pressure and not variable pressures. You also don't have to worry about a back-flow valve, one additional fail point on a system.

That’s really kind. Welcome and I hope you find more that is useful!

Also, exit losses will be different and "A" has one more elbow. The analysis in the video is quasi-static. There's nothing wrong with that, but it should be mentioned.

Side note: It should be calculated for 3 meters, it was 10 feet

No tank is always full. A pumps always 3m. B and C don't have to pump the missing height.

What I like about A is that if you turn off the pump, the fluid stays in the tank and doesn't flow back (only the portion in the pipe)

@@CatNolara Yes, this is true.

It does use less for the reason you just said. The video was just explaining that only the head matters, not the total volume.

other thing i hear people saying is that in 1 you will save pumping energy by filling from the bottom, because you won't be working against the full tank head when the tank isn't full, whereas if you fill from above you will be against the full head all the time. But in reality that does not work that way because the pump will work as its curve says .initially you will have less H and more Flow and the eficiency will be different.

@@zerocanvas6163 you assume a centrifical pump. why do that.? much liquid pumped into tanks is actually pumped with lobe pumps where the flow will almost not change with head but power will.

@@ronblack7870 At the place where I work (olive oil processing plant), centrifugal pumps are used for tank filling because the filling flow rate is the most important factor (it must be fast). Positive displacement pumps (gear pumps) are used to transfer the oil from the storage tank to the bottling line.

A simple check valve will prevent it from leaking if there's a failure. All sump pumps have this, although they have it to keep the water from the vertical pipe from flowing back in to the sump, but it would still work to prevent a week in the event of a failure.

There is no difference in the transitory state of pressure. In #1, the same pressure variation will occur when filling the riser as when bottom filling the tanks. The difference is that the riser will be filled quickly and, once filled, the pressure to fill the tank remains constant. Whereas bottom filling, the pressure varies over the entire time required to fill the tanks, from start to finish.

Yes, and note that this only considers the hydrostatic case. To see that the hydrodynamic case can be different, consider the swimming-in-the-ocean example, but with an impending tidal wave. In water retention systems, this shows up as "water hammer", and is a major engineering challenge in some situations.

Yes, roughly double the thickness of material is needed for the bottom compared to the sides for aquariums mounted on a stand that supports the bottom only by the rim. There's an exception. If an extra support band is added to the center of the bottom glass, that reduces stress and similar thickness can be used. In practice, if set on a solid level surface, thinner glass could be used since it'd now (mostly) be there simply to seal water in. That's one reason why huge aquariums (and bathtubs) are often set atop thinset (cement) for additional support.

Not exactly. Weight equals pressure. Bottom carries pressure, which equals the weight. The reason the bottom is thicker is that the pressure is constant all across the bottom, whereas the force on the side is the average of the pressure at the bottom and at the top. Top is zero, so force on the side is roughly half of the force on the bottom.

@@bipl8989 Correct, but it's the unsupported dimensions that matter. Let's say you have a 30x60 bottom. If you add a center support, each half of the bottom is now a 30x30 distance, roughly half the weight. You see that in buildings, as in using posts, load bearing walls and foundation supports below floors.

Yes, and he did mention that.

Less energy needed for bottom fill, since all fluid does not have to be lifted over the top of tank rim. Less energy is needed in bottom fill since the pressure (height of lift) is much less during the initial stages of filling.

100%

_Never more than_ the full level would be more accurate. In the diagrams, there is some distance from the top of the tank to the upper fill port. If the fluid exceeds this, then the heights become equal.

Not true.

No that’s not it. The height determines the back pressure, regardless of the shape of the tank.

you are correct, but fluid dynamics and fluid viscosity will also play a roll. In theory, an open ended pipe will have less resistance to flow, even though it will have the same head pressure at the same height. You also have the advantage of a siphon breaker in the event that something fails in the pump system.

A siphon works due to a difference in elevation between the inlet and the outlet. If the ambient pressure at inlet and outlet are same, then the outlet must be lower than the inlet for a siphon to work.

Have you check out this one? Liquid line sizing & pumping downhill kzfaq.info/get/bejne/bLqHgZqGz966oXU.html

It’s about how far the brake pads travel in relation to the brake pedal. Think of the lever, lets say one edge is 40cm away from the fulcrum and the other one is 10cm away. The farther end travels 4x more but gives you the mechanical advantage of providing 4x the force at the other end. Same thing with a brake system. You’re kinda putting little force on a long thin tube and getting more force at the other end with a big short cylinder. This is not a perfect explanation but I recommend you look into it on the web 🤞

Technically yeah, but it's not the point of this video