The Physics of Water Pumping

Are you sure your gauges work fine guys?

You have lymph vessels everywhere you have capillaries. Interstitial fluid can generally move freely around the cells/tissue so it will tend to distribute itself evenly. It only pools locally when there’s an excess concentration of protein (which are supposed to be removed by the lymph system as well).

Regarding the glans: Have you every done 60 minutes in air? Or 30 in water? It could also be a sign that the meatus is more sensitive and swells quicker than the surrounding tissue.

No ;)
It’s 9 months old and one of the plastic ones you can buy from thickwall. But even if the calibration is wrong that shouldn’t change a comparison between two media.

I doubt that.

Doubt what? That the gauge would show the same pressure for either medium despite being off in calibration?

Regardless, my argument isn’t based on observations (rather supported by), but on the workings of fluid mechanics.

Excellent point!

My contributions on gauge accuracy are in this thread:
Anyone using water lift to measure/regulate vacuum?

I have a digital pressure switch that is used on the electric pump system sold by Mr. Fantastic. The digital pressure switch is much more precise and accurate at all ranges of vacuum while the analog gauge (brake bleeder) is not accurate at the lower range (less than 15" Hg) and lacks precision (hard to read). Note the difference between "accuracy" and "precision".

Regarding threads staying on topic - I’m NOT the thread police but in the long term (5 years from now) mixing too many topics on 1 thread makes it difficult to research a single topic such as "dynamic pumping" since key words used for search results are not always present in every relevant post of a mixed topic thread. However, a thread like this one is very valuable (regardless of mixed topics) because of the insightful men participating - Thank You!

I am interested in anything that will improve the Pumping form of PE. For me, one of the primary complications of pumping is unwanted lymph edema, while other guys might be pumping FOR wanted edema. Therefore heat, water, silicone sleeve (the new version of condom pumping), and dynamic pumping are all relevant to me. Perhaps I am just stating the obvious…

From the posts so far (on water pumping) it seems that this technique results in less unwanted edema than air pumping at similar vacuum and duration. We still face questions of how much vacuum, hold times and the duration of cycles (static vs dynamic) to achieve our own individual goals. To further complicate PE matters, it seems like what works for 1 man does not necessarily work for another man.

Well, technically pumping physics includes both dynamic and static pumping. :)

High accuracy is not necessary as long as the gauge is consistent.

People consistently reports less fluid build up with water pumping, at same pressures. If, as you say, the medium doesn’t make a difference, than they are lying or their gauge is broken; the other chance is that you are wrong and your theory is lacking of something. That’s it.

Agreed, nearly 5 years of experience doing both air and water and at the same pressure edema and bruising/red spots are less with water.
If the actual pressure is the same there must be something else at work.

Well, I’m not wrong, I know that much.
:)

I don’t recall having seen an actual comparison at high vacuum readings. I would be interested if anyone can point me to one. I’ve seen plenty of reports for lower vacuum levels / long duration pumping, and I’ve explained why that happens.

There simply is no interaction between the fluid in the tube and that inside the penis. Only a pressure difference - and that only differs in the way that I’ve outlined earlier. If someone truly does get significantly less edema in water at high vacuum levels, then the only option is that the pressure difference created by the water has a bigger effect than I would expect.

One factor is the more constant heat with water. Anyway, I know it sounds like I have a fixed idea, but the medium does makes a difference IMO. That’s why I made the example of sand. It would create even less edema and the pressure would be felt more toward the top (if the cylinder is pointing down). That’s what intuition suggest to me, never tried pumping with sand. :)

Wow, there were a lot of responses while I was sleeping!

Copernicus, your idea for a water vac hanger is a good one, I have thought of this before and think it is an interesting idea for vac hanging possibly heavier weights with less slippage. Possibly even a lower vacuum to weight ratio. Although it seems like blisters could become a problem.

Austfred, the lymphatic system moves lymph around through smooth muscle contractions and valves, and also through skeletal muscle contractions, circulatory system pulses, capillary action, and gravity. Fluids travel into the lymph capillaries one way through cells that act as doors. Fluid cannot travel back out this way as a higher pressure inside the lymph vessel relative to the outside causes these “doors” to close tighter. When pressure within a lymph vessel becomes high enough, however, it can escape back out through reverse osmosis and leakage through the valves. This contributes to edema.

Edema, however, is mostly caused by the inflow of interstitial fluid from the body. The lymphatic system is mainly there to carry overabundant fluid back to the blood stream. When we pump, the vacuum causes lymph to push into the lymph vessels in the penis and interstitial fluid to seep into the soft tissues as well. My point in going into all this is that edema is a complicated process and it is hard to say what it is about the fulcrum stretches that are causing it. But you know they do, and you seem to have found ways to mitigate it, and that’s really all that matters. :)

Serenity, nice to see you back! I basically agree with what you are saying. And it is definitely true of purely static pumping. The more a system is filled with liquid and the less with gas, however, the less penile expansion will need to take place to equalize the pressure. So unless you are constantly eyeballing the gauge to keep pressure constant you will have an expand quickly-expand slowly until pressure is equalized-hold scenario until you pump again to evacuate more fluid. If you re-pump every five minutes with a system mostly filled with water, and you aren’t pumping to some absurd pressure, you will minimize the gradual expansion phase where most lymph and other fluid enters the soft tissues.

Also, there is a threshold for edema production with water pumping, I believe. That is, lymph has to travel across membranes, there is positive water column pressure acting on the penis, the water is warm, the water has a much higher heat transfer coefficient and heat flux density than air, etc. The net effect of these factors is a minimum safe vacuum where edema is minimal, and the less you breach this arbitrary threshold, the less edema you will produce.

That would be a sight, wouldn’t it? Wandering into a playground to fill up your cylinder.. “Don’t worry, it’s.. uh.. for a sandcastle”.

It’s an interesting thing to do. I’ve never used a vacuum attachment myself. If blisters sometimes happen as a result of friction between the material and the skin, then water might actually be safer. Of course most blisters are probably a result of the prolonged vacuum but with the expandability of air and the silicon (is it silicon?) it’s possible that there could be some shear stress on the skin surface, which would largely be mitigated by filling the cap with water.

Yes, I briefly mentioned that earlier to cover all bases. Part of the discussion just comes from me being a stickler for details in scientific topics. I take it very literal and I just want to make the distinction between the inherent properties and other factors that might come into play because of the presence of water (temperature, rapid pressure variations, etc..).

I’m not following this.

Serenity, those factors I listed tend to help in preventing edema allowing you to produce less edema at a given vacuum level. Constriction (condoms, silicone sleeves) should also be on that list. Only with water, however, do you get the benefits of water column pressure and improved heat transfer dynamics in all cases. These properties would allow a bit more vacuum to be utilized, even statically, without causing a ton of edema. This is what I am referring to as a “safe threshold.” This safe threshold would be a bit higher with water. You have basically already said this, I am just putting it in those terms relating to vacuum pressure.

So relating to more standard pumping, when you pump up and the pressure begins to fall as the penis expands it will fall faster the more water you have in the system due to the (lower than pure air) net compressibility of the fluid outside the expanding penis, and the very low edema threshold will be a slightly higher vacuum level with water, so the time you spend in the edema-heavy range will be less.

I merely point this out to show that in an infrequent re-pump scenario the pressure doesn’t need to fall all the way to equilibrium to minimize edema. But as you have pointed out, none of this holds true for a truly static/constant vacuum that exceeds this arbitrary low edema threshold.

Roots

To make this thread more complicated, I suggest there might be more involved with water pumping than just physics (i.e. fluid dynamics and heat). As we all know, the penis is a complex part of anatomy - various types of tissues, vessels, fluids and nerves (sympathetic and parasympathetic).

Consider: how and why do fingers and toes wrinkle when under water? I am not saying the penis is the same as fingers and toes, but rather using this example to illustrate a concept.

For well over a 100 years (and even today), researchers have theorized how fingers and toes wrinkle under water:
temperature?
keratin absorbing water?
osmotic pressure?
vasoconstriction?
electrolyte balance?
neurological influence?

I will avoid all the theory details and skip to a few observations to make my point: At one time researchers were convinced keratin was the answer and they were later proven to be wrong. People with nerve damage in some fingers but not others noted that the nerve damaged fingers did not wrinkle. If electrolytes are involved then why do fingers wrinkle and other submerged skin does not? Lots of questions remain unanswered about this anatomical phenomena.

So, my point? The penis underwater might have a lot more going on than just environmental pressure and temperature (physics). I suspect biochemical and neurological influences contribute to the anecdotal evidence that water pumping produces less edema.