The Physics of Water Pumping

Sounds like a lot of good theory. In my experience the benefit is from the hot water.

Actually, water column pressure depends only on depth, not the area of the column. Doesn’t seem logical, but when you consider the force vectors that generate the pressure press straight down in the direction of gravity, it might be a bit clearer. The formula for this type of pressure just uses height, the density of the liquid and the acceleration due to gravity.

Seems like a lot of over thinking in my opinion.

Oh God, it has gotten to that point hasn’t it?! The point of the initial post was to show what is really going on when you pump. There is no such thing as “pulling.” Expansion force is internal. Pressure is not the only meaningful aspect involved with pumping.

Oh well, I enjoy talking science. :)

It is nice thread instead IMO.

Is there any correlation between a longer cylinder then and pressure? If a longer column exerts more pressure, would opting for a longer cylinder irrespective of actual need (rule of thumb; actual length + 2”) then have a positive effect?

As you can tell by my lack of posted routines, I try and stay away from science. I stick to what works. Water pumping is the most effective pumping method in my opinion. The downside is the added time it takes.

Correct, let me perhaps clarify the process in pumping with water.

First, creating a partial vacuum at a given level in a completely water-filled system produces very little change in the water’s density. That is, not much room is created for the penis to expand into - room that comes from the expansion and compression of the medium that is. So for every unit of water evacuated the penis must expand about one unit. With air, one must evacuate much more air to create the same initial expansion force because air is expandable. This means that the penis can expand a great deal more before the pressure equalizes and an equilibrium is reached. (So Marinera, you are right here, but it’s not really a good thing)

This slow, constant, and greater total expansion in air is what leads to higher fluid buildup as fluid inflow is much harder to achieve than blood inflow. The almost 1:1 evacuation:expansion ratio with water also gives the pumper much more control to expand primarily the tunica. That is, you pump up to a fully erect state, when the tunica tissues relax viscoelastically you evacuate water again as there will be less resistance to blood inflow at that point. Doing this, you ensure more of the total expansion is from tunica expansion rather than fluid retention. You cannot follow this modality with air because it is compressible/expandable.

So just like all other forms of PE we should concentrate on achieving the desired amount of stretch in our target tissues rather than the negative pressure generated. I mean, don’t get me wrong, pressure is useful from a safety standpoint, but one of the main points I was trying to make is that it is not the end-all, be-all measurement in pumping and the expansion we get from it.

Why entered in a thred like this then? :D

This is really only important when speaking about water, but yes, a longer cylinder will produce a greater positive pressure gradient when going from ceiling side to floor side if it is filled with water and aligned vertically (perpendicular to the floor). But why would you want that? I would think having a larger pressure differential from top to bottom would be undesirable.

rootsnatty

From your statements it seems that with water pumping you’d need to keep increasing the pressure - once you stop the pressure, and fluid leeches between the tunica and skin, it’ll collapse the tunica as fluid increases. Maybe water pumping is superior as long as pressure is constantly increasing. Air pumping would be superior for marathon pumpers that stay withing certain pressure. I’m just making assumptions - I could be incorrect.

I think water pumping would actually be best for marathon pumpers as they would have more opportunities to cause greater expansion.

And the problem with fluid retention isn’t that as it accumulates it pushes in and compresses the tunica, but that it happens at all. The more fluid retention, the less of the total expansion will be from tunica expansion.

Thank you, that’s much clearer :up:

It’s a fair point as far as the initial stages of pumping up from flaccid go. The gauge should drop to 0 (or close) immediately after each pump and the penis is kind of “held” at a given size by an inability to contract, rather than stretched to it. But as soon as you elicit an elastic response from the tissue, you’re going to get a buildup of potential energy which will hold a partial vacuum. As long as the needle no longer drops to 0, you’re basically in the same situation as with air.

That said, a month or two back I was actually thinking about using the same concept to create a sort of all-day pumping mechanism. I wanted to make an airtight mold of my penis and put it on while erect so as to maintain an “erection” (erect size at least) for as long as the mold was attached. Never got around to looking at materials for it, though, and I’m not sure it would have enough blood exchange to be worn long enough to be useful.

Exactly!

I actually have a funny story that applies exactly to this. I posted it in my progress report thread, but I will summarize it here:

My girlfriend wanted to try joining me on my tissue expansion journey, so we got her a breast pump. We tried it with air first and it worked basically how you would expect it to. Then I hooked it into my brake bleeder and we tried it with water. Things went haywire here. I was staring at the gauge and nothing else. Each time I pumped the pressure would spike extremely high and immediately fall back to zero. I, of course, figured there was a bad seal. So after going through four full reservoirs of water, I finally looked up. Her boob had COMPLETELY packed the cup and the pressure was still at zero on the gauge. There was a tiny bubble of air at the very top of the cup, and the only edema she got was right where this bubble was.

So once I saw what happened, it made sense. The breast has no connective tissue to resist expansion so no matter how much water I evacuated, the breast would immediately expand to fill the void, offering no resistance. This would cause the pressure to equalize showing a zero on the gauge. The penis can achieve this until its elastic limit, then further expansion of the tunica can only happen once it relaxes viscoelastically.

This is exactly what I see when water pumping, over the course of 30-40mins I keep having to pump to maintain pressure and my overflow jar slowly fills up.
Given the lack of edema and air bubbles in the cylinder the volume of water in the overflow must somewhat relate to the volume increase within the penis.