Increasing IP Does Not Help Breathing - Scuba Tech Tips: S13E07

[@Lordvader330]

In the year I have been watching Alec’s videos I have learn a few things. 1) get your gear serviced once a year by a professional. 2) the “factory” designed regulators to work within a set spec value. Don’t mess with that value! Thanks again Alec. I have learned a lot in this year. I have been diving since 1990. Learning new things is a blessing.

[@AlecPeirceScuba_SeaHunter]

Thanks for that Lord Vader. May the force of scuba be with you. A.

[@toriless]

Just like a car

[@Caderic]

Again...GREAT video. I love the tech specs and related info! Watching your videos, diving and ranch videos, makes me wonder if you a a "Believer". No to talk politics or religion, but often there is something about believers that just sticks out.

[@AlecPeirceScuba_SeaHunter]

Having been luck to get this far in life given many of the crazy things i have done over the decades, I believe someone is watching over me. Thanks Erikk and take care. A.

[@DigginwithSeven]

Another great job if explained the relationship between HP and IP

[@AlecPeirceScuba_SeaHunter]

Much appreciate your feedback Seven. Thanks for watching. A.

[@khalidalaudin616]

Hi Alec. Great videos you have. I would like to know with the MARES Prestige second stage don't we need to remove the hose form the second stage and adjust the second stage IP by adjusting with an inline adjuster tool on the side where the hose is attached to? In your video I see that you adjusted it on the other end of the second stage.

[@AlecPeirceScuba_SeaHunter]

Each reg maker has their own unique setup. Some are opposite the hose, some on the hose side. I don't have any information on the prestige (no longer have my books) so can't help. Maybe ask this on www.scubaboard.com to get feedback from the wide diving world. A

[@rickkinney2544]

Appreciate the useful information as always.

[@AlecPeirceScuba_SeaHunter]

My pleasure Rick. Thanks for your support. A.

[@peterjulianphotos4659]

Alec I think you should rename your channel to "Underwater Mythbusters" - well done again. i think you will find that the people who overcrank their regs also do weird stuff to their 4x4s, and are over represented in hospital hyperbaric units.

[@AlecPeirceScuba_SeaHunter]

HA HA that's a good one, 'over represented'. I'm going to use that term thanks for the laugh Peter. A.

[@jacquespoirier9071]

it is a question of balance between the incoming pressure and shut off valve on the second stage, to have the regulator functionning as required, the most important is to reach the point where the slighest pressure on the second stage diaphragm cracks the inlet valve. For sure, the designers have tested calibrations so adopting their recommendations is the best starting point. I observed that on some type of regulators, a slightly too high IP have a tendency to induce fluttering when the regulator is used underwater, not as perceptible when operated dry.( I believe that it is due to the inertia of the water facing the diaphragm. a very good topic.

[@AlecPeirceScuba_SeaHunter]

Thanks Jacques. Read through the comments as another view shared his experience servicing regs and always sets the IP middle of the makers specs for easier trouble shooting. Take care. A.

[@moclepocle]

Alec, I have been doing it wrong for 30 years. Thanks for your wise knowledge.

[@AlecPeirceScuba_SeaHunter]

No worries! I still learn new things at 75. A.

Dear Alec its enjoy to learn from you. I am using calypso regulator (98y) servising every year! Its more of them, some have IP 5.5 bar some 6, some 7.5 bar ( at cylinder pressure 70bar)! I think materijal of spring ,or metal are used to many. But i am still using ,diving,servising...my question is what is lowest IP available . What is tip? Thanks a lot

[@AlecPeirceScuba_SeaHunter]

I don't have current service manuals on all Calypso first stages but the manual I have for a "Calypso J No. 1048-00 says " Standard intermediate pressure is approximately 128 psig at 2000 psig supply" . Remember to test the IP with an accurate gauge. A

[@pinnacledivingco]

I love that you did this video! 😆 The best advice I can give people about diving in cold water is, once you submerge the regulator, do not bring it above water until after the dive is complete. The cold air once it’s wet is exactly what freezes it up. When I service regulators, I typically adjust the IP to the middle of the range, simply because it makes it easier to troubleshoot any potential problems later on if the IP raises or falls or creeps. I once heard an argument from a fellow tech diver that increasing the IP would allow for a deeper dive when ATA approaches the same force as the IP. Not only is he not going to reach that depth, so there’s no reason, but exactly as you explained, being forced to increase the cracking pressure in the 2nd stage has the opposite effect, and is exactly why the manufacturers recommended range exists.

[@AlecPeirceScuba_SeaHunter]

Thanks for the feedback PDC, your real world example is what my point is. Funny how a diver with 200 dives (example), knows more that every engineer, test engineer and design engineer at say ScubaPro. Good to know some information on KZbin (meaning mine), is actually factual and helpful. Take care. A.

[@timgosling6189]

Absolutely right, and in the age of balanced regulators any depth related issues have already been taken care of. Don't mess with it!

[@ICEMAN_ADVENTURES]

Happy Thursday

[@AlecPeirceScuba_SeaHunter]

You too. A.

[@timgosling6189]

I hadn't heard this one. Isn't it obvious that the demand valve has the final say? Anyway, the other way of looking at it is that the human body is also designed to work at normal atmospheric pressure: you suck gas in and relax the chest to let it out. So if you increase the pressure of gas going into your mouth it will help you inhale but it will also make you work to exhale, rather than just relaxing the muscles. The body don't like that, it's unnatural and you will use more energy and burn more air doing it. In my previous career I had occasionally to use 'pressure breathing' for situations where even at 100% there just wasn't enough ppO2 to keep you going. That used a regulator where the gas was physically forced into you and would keep coming until you physically forced it out. It was incredibly tiring! To get the best possible gas consumption while diving breathe normally, regularly and deeply, and relax. Mastering buoyancy, trim and efficient kicking will do much more for your SAC than messing with your regs!

[@AlecPeirceScuba_SeaHunter]

Good tips Tim. But there are divers and Darwin Award winners who just must "tune" and new factory reg to their version of perfect not knowing the inter-dependance of everything. Oh well a new dive season approaches and lets see who is here in the fall to learn more from this old stone age diver. A.

[@toriless]

Wrong, you expand the diaphragm to exhale, take an anatomy class. You clearly have no clue.

[@toriless]

Only the last matters, most air is consumed by involuntary breathing. You will learn more about breathing and human anatomy in the first two chapters of a free diving book than in dozens of SCUBA books. Also some great breathing regimes any SCUBA diver could benefit from.

[@timgosling6189]

@@toriless Let's keep it respectful. But after many years of aviation medicine training I believe I have at least a bit of a clue. To quote from my first Google result, the British Lung Foundation: "[To breathe in] the diaphragm is pulled flat, pushing out the lower ribcage and abdomen. At the same time, the muscles between your ribs pull your rib cage up and out. This expands the chest and draws air into the lungs. [To exhale] is mostly a passive process. The muscles you use to breathe in now relax and your elastic lungs push air out." As you exercise harder and need a faster breathing rate the body does employ active muscle power to breathe out, but that shouldn't apply to most scuba situations. The point stands that pushing air in under higher than normal pressure and then having to use muscle power to force it out when you wouldn't normally does not allow the body to operate at maximum efficiency. I hope this helps.

[@chamnanchaichansuk9647]

Hi, I'm a big fan from Thailand and I have a question. Is it necessary to adjust the lever height of second stage if I found a perfect matching IP and cracking pressure by using an inline adjustment tool? Thanks in advance.

[@AlecPeirceScuba_SeaHunter]

Yes. Even if the IP is perfect & the cracking pressure has been set to suit your breathing, a gap between the lever & the diaphragm will obviously delay, even if slightly, the activation of the valve. The diaphragm has to travel that small distance before contacting the lever. That requires both inhalation effort AND time, however small. You can often hear a loose lever by shaking the 2nd stage while the reg is pressurized. The lever will often bang back & forth between it's set position & the diaphragm pad causing a rattling sound. To be frank, it's not a tremendous issue and for regular diving won't cause a problem. But it purest technical terms, yes! Alec

[@chamnanchaichansuk9647]

@@AlecPeirceScuba_SeaHunter Many thanks Alec.

[@maxtorque2277]

Interesting video Alex! if only it were actually that simple :-) Firstly, Work of Breathing (WOB) is actually dominated by the exhalation portion, because our lungs have to push the exhaled air out across the exhaust flapper valves and into the dense water around us. Inhalation is a low amount of work because we can use the pressure drop from the IP down to our lung pressure to drive the air into our lungs for "free" so to speak, this is the common "venturi" effect (where fast flowing air creates low pressure that helps to pull the 2nd stage diaphram inwards, and therefore reduces the WOB Secondly, in a basic unbalanced second stage, the orrifice spring is acting directly against the force created by the IP on the effective seat area. This is why you need to wind on more spring pressure to prevent freeflow with a higher IP, you need that spring to press harder against the incoming air pressure. This means of course that the NET force required to crack the Demand Valve (DV) is not increased (im going to ignore the tiny effective increase in spring rate here for the sake of brevity, simplicity and well, KISS eh :-) With more IP, the air density is increased however, so for any given volume of air at ambient pressure the seat needs to open a smaller distance, and this IS work done, because opening the valve must over come friction, and with higher loading (despite the same NET load as mentioned) there will be more friction and hence that requires more work to be done on the DV by the diaphram, which is ultimately provided by your lungs and the incomming air stream (see point 1) What is certain though, is that these effects are very small across the range of IP's that realistically one would ever use, and in fact, it would take a precision WOB testing machine to see any difference. A diver might feel some difference though, with the DV feeling a bit "sharper" is suddenly supplying more air in a short sharp burst, rather than in a longer "smoother" one, and this tends to trick people into thinking they have made more of a difference than they actually have :-) And finally, note that on a modern "pneumatically balanced" second stage, where the IP is actually fed to both sides of the DV (and so practically negates the area of the seat loading, the IP in effect pushes against itself via clever system of holes and tubes through the DV mechanism, really practical changes in IP have effectively no effect until you get to such high pressures as to reach the deliberate "blow off" pressure of the balanced DV or reach the max seat opening area limit, which unless you regularily dive to >100m is so large in a modern 2nd as to be irrelevant :-)

[@AlecPeirceScuba_SeaHunter]

Wow! Nice long response. It deserves an equally complete reply. However, you have made some assumptions that are not necessarily accurate. Since those assumptions do NOT apply to my video, your comments do not apply. Remember, the video was "Increasing IP Does Not Help Breathing". That basic premise is quite true. There are many, many additional factors to be considered by a service technician. I did not talk about them for 2 reasons: 1. they have nothing to do with the basic premise &, 2. they would be beyond the interest or expertise of the average diver. 1. There is no venturi effect unless the regulator design allows for it. A standard 2nd stage does not get any benefit from the venturi effect. Moreover, there can be no venturi effect until the air starts to flow. That is, even in a regulator design that optimizes the venturi effect, there is no benefit to the diver until the airflow begins - and that is AFTER the 2nd stage valve opens. The inhalation effort required to open the valve to create that airflow is not affected by any venturi effect. Venturi effect is not an issue in this video. I can easily make a video about regulator exhalation effort, how it affects the diver & the many, many efforts over the years to minimize it, with limited success. You are quite right that exhalation effort is a major issue, possibly larger than inhalation effort. 2. While some of your assumptions regarding spring pressure vs IP pressure are fair, there is definitely a difference when the spring is compressed beyond the manufacturer's specifications. I have demonstrated this myself in regulator service training programs. The immediate effect is to "sharpen" (to use your terminology) the opening & closing of the valve which I have likened to a screen door on a cottage. When the handyman fixes the spring, suddenly the residents notice the door is harder to open, then it springs open more rapidly and it will also catch their heels as it closes, all unexpected results from the tightened spring. This apparent effect is because of the increased effort required to open the valve. By design, spring rate increases as a spring is compressed. The force required to compress a spring is not linear. That is, a spring exerts more pressure, and requires more effort, to change its length as the spring is compressed. Or, if you like, a spring that is lightly compressed needs less effort to compress than a spring that is highly compressed. The forces acting on the valve, spring on one side, IP on the other, are still balanced as you say, but it requires more effort to open the spring. That is one reason why using a manufacturer's spring AND setting the IP to the manufacturer's specs is important. All of those forces were meticulously designed to create a consistent, smooth effort. Spring rate IS a factor and should not be ignored. 3. As you say, the increase in density resulting from an increase in IP of perhaps 5 or 10 psi would be immeasurable and is not a factor. However, the seat still moves or opens the same amount. This is a purely mechanical device. When the diaphragm is depressed by suction, it presses on a lever. The lever presses directly on the poppet valve to open the valve. With a fixed depression of the diaphragm, the lever moves the same distance & the poppet moves the same distance. The length of time that the poppet is opened may be shorter with higher IP - hence the screen door "slamming" effect. There is NO INCREASE IN FRICTION. For friction to change there would need to be a change in the mechanism - more parts, less lubrication, greater lateral force, etc. The lever rests on the diaphragm pad. The other end of the lever rests on the poppet valve indentation. There are only 2 points of contact. There is no lateral (from the side) change. The friction does not change. Any apparent or real change is the result ONLY of the relationship between the spring & the IP. 4. A balanced 2nd stage conforms to most of the same principles other than the fact that changes in IP have minimal changes to load. There is a well-known set of Four Laws regarding Downstream Demand Valve Adjustments. They are called laws because they are immutable and apply to every downstream valve regardless of design, balanced or not. The Laws Of Downstream Demand Valve Adjustment are: 1. The cracking effort of the valve is a direct result of the force required to depress the lever. 2. The force required to depress the lever, and open the valve, is a direct result of spring pressure. 3. The spring load required to seal the valve airtight is the direct result of overcoming IP downstream force, plus the seating force factors. 4. The lever must always be adjusted to maximum height to ensure full poppet/orifice separation. I recently made a video about an incredible book by an acquaintance, Pete Wolfinger, a long-time employee of Global Manufacturing. They are the largest supplier of testing equipment to the dive industry and have been a leading developer of scuba testing & repair equipment . Based on your obvious interest in the intricacies of scuba regulators, if you don't have this book, get it. You will be amazed at the wealth of detailed knowledge in it. You can see that video here kzbin.info/www/bejne/Z3K4Z3yGnLGZac0 . Thanks for your comment. Alec

[@toriless]

There is a difference between an "unbalanced" system with higher IP and bigger springs than taking a "balanced" rig and increasing the IP to an unbalanced level as in this demo. To be clear he is stating modifying a rig for higher IP is bad not that a system designed to deliver a higher IP and uses a different design is bad. Also the VAST majority of any breathing is involuntary. The a mount of air movement by inhaling and exhaling is a very small amount on the total usage. Most of this does not have enough force to open a valve, it is exhaled along with the used air you can control directly.

[@matthewhignite]

what is the best way to store fins

[@AlecPeirceScuba_SeaHunter]

Rinse, dry completely and put away. Rinsing is very important for steel spring and bungie straps that are affected by salt water. A.

[@toriless]

Rinsed, dry and with air around it, however regulators should be rinsed, dried and in thick plastic bag for long term storage unlike fins and masks.

[@stuartcareless9550]

It would be interesting to know what the average dive time on a standard tank of air is ?

[@toriless]

No such thing, it depend on where you dive, duration is most dependent on depth which depends on dive location. Even of you did calculate it the results would bee 100% useless. At least with OW cert only people the numbers would vary less. In the PAC NW you often have more depth than in vacation dives where life is right on the surface but even here you can find dives that only need 30 feet of depth but in HI you can go only 10 feet and still have a nice view. A far as a standard tank, you can assume AL80 or SS100, If I had money I would use SS80, size of a AL63.

[@stuartcareless9550]

@@toriless Some great points let's stick with vacation dives in the warm at 30 feet. Dive schools take people out and they must have a ruff time they would expect on group dive.

[@AlecPeirceScuba_SeaHunter]

It's like saying distance on a tank of gas for a car. So many variables from people, wind, baggage, traffic, driving style and so on. Dive computers will help log your time and practice can extend it. A.