Low Pressure vs High Pressure Air Loss Test

what's up guys it's Brian again from play kicker skimmer and I got mr. Steve Nash here he's one of our local divers he does water local diving in one of the quarries and Steve sent me an email here a couple days ago asking if I could shoot a video catastrophic failures or free flows underwater but I'm going to take it one step further we're actually going to do several catastrophic failures tonight in the pool but before we do that I'm gonna let Steve tell a story of exactly what happened so we know what deputy was at how quickly this failure occurred and how quickly he actually ran out of gas at then so Steve appreciates being alone and definitely appreciate you being our subscriber with us if you will to our audience just a little bit about what happened to you and that way we kind of know how to set this scenario up see if we can simulate exactly what happened and try to learn we were about 10 15 minutes into the dive at about 50 feet I normally do a couple of regulator switches and with my primary - my necklace back up swim for a few minutes switch back when I pulled a secondary out restorative free flow of breath so I did what I knew I thought I'd do so stop everything all right stick my thumb in there trying to free Johnny in the back pressure right exactly nothing worked spent probably about 30 45 seconds trying to fight that Bank and I noticed reading resistance so I immediately went to my SPG and I was close to about a heart pounds all right I carried a bailout so I immediately went to the bailout good thing you had definitely glad I got myself relaxed and a few seconds later the SPG only me that gas was at zero kid so I notified my buddies gather that and then we send it safely to the safety stock awesome well definitely glad you made it back that's definitely a scary story with all means and yeah you know free flows can be calls from anything from a regulator freezing up you can have debris and one of your diaphragms that can cause a free flow as well maybe your demand will ever get stuck anything like that can cause a free flow but what we want to do tonight we're gonna simulate a free flow at the extreme we're actually in a jump in the pool when I've got three tanks set up once people are gonna actually cut the high-pressure hose as if you maybe had a gauge explode or maybe the swivel or the spool inside the gauge exploded we're also gonna cut a low pressure hose now we can sit there and just hold the purge to simulate that free flow we want to take it to the extreme we want to see exactly what happens when a low pressure hose explodes and how long it takes to drain and then we're also going to simulate a high pressure free flow as in your actual oring of your tank valve flows out or malfunctions underwater to where you you were actually having to shut down your valve underwater so we're gonna tom all three we're gonna before you see how long it takes and then when I get done edit into this video I'm gonna do the math for you we're gonna try to simulate everything that happened to him at 50 beat here tonight and we're only dealing with a ten-foot pole but we can do the math and see if it's consistent that what actually happened and then I'm also going to show you why it happens wild one bleeds off quicker than the other and why he went through his air so quickly so let's jump in the pool and then I'll give you some final thoughts when we get done Shh Oh [Music] alright guys so we just got back to the classroom we've got all the numbers around here and they are very very shocking I want to do a quick recap of exactly what we did how we tested this how we calculate it down and I also want to show you the primary reason these numbers are what they are so first of all we had three cylinders that we tested all at a depth of 10 feet or 1.3 atmospheres that works down to three point zero four meters for the metric crowd out there and of course what we did was simulate a catastrophic failure in different systems we tested a high pressure and a low pressure line and then we also tested just a catastrophic failure in the valve itself one thing I want to make quick note of if you'll take a close look at the two ports here the top one is a high pressure line going to a gauge the bottom one is a low pressure line going to your second stage you your primary your alternate and as you can clearly see the bottom one has a much larger port to allow more air to come through so when you see the results you'll understand why on a free-flow or a low pressure catastrophic failure why air goes away much quicker than it does on a high pressure so once again high pressure low pressure and valve on the 50 cubic foot this is where we cut the high-pressure hose we had a bleed off rate of 56 minutes to bleed that tank off at 10 feet now if we converted that to say a sack rate or a breathing rate for a diver that would be approximately 40 1.20 psi a minute that is extremely high but that would be say the equivalent to a new diver maybe he's out of shape maybe he's been fighting a current or he's been doing some type of underwater work so yes it's high but it's not too awfully high that's a point six eight cubic foot our env rate if we was to take that diver down to 50 feet or two point five one atmospheres or for the metric crowd they'd be 15 point two four meters he would have approximately twenty nine point four minutes of air time remaining now if that catastrophic failure happened at a depth of 50 feet he would have almost 30 minutes time just to make it back to the surface so yeah it's a dangerous situation but it still gives you plenty of time to make it back to the surface if you're alone or by yourself and you couldn't get to your buddy moving over to the 53 cubic foot tank this is one we cut the high-pressure hose to simulate say a free flow situation you don't took three minutes at a depth of ten feet to bleed off that tank now if we converted that to say a breathing rate once again there'd be a seven hundred sixty nine point two three psi per minute sacré that is extremely high his rmv would be almost 14 cubic foot a minute it's exactly thirteen point five eight cubic feet now if we took that diver down to that 50 foot mark he would only have a minute and a half of time for him to survive on that air now at a depth of 50 feet with an ascent rate of foot every two seconds she would need approximately a hundred seconds to make it to the surface he would only have enough air to make it in a 90 second timeframe so a hope you see just why it's so important and like I showed you on the hoses the difference between the high pressure and low pressure port that is why there's such a large time difference they're moving over to the 63 cubic foot this is where we did the valve mount malfunction such as say a blown o-ring it took 13 minutes to bleed off the tank at a depth of 10 feet if we converted that over to a Sacre for a diver that'd be approximately 170 7.51 PSI minute or our MV of 3.72 cubic feet and of course if we took him down to 50 feet he would have approximately six point seven four minutes of air time to make it to the surface so that's still extremely high but it's a little bit better than say your low pressure hose malfunction or having a catastrophic failure so guys there's the numbers the low-pressure is very very scary I hope you can understand just why it's so important to be able to deal with say a free-flow underwater and even more important to test your gear before you ever get into water and I would say even more important to make sure your gear is serviced on a regular basis meaning whatever the manufacturer states that's when you should get your gear serviced if you want a little bit more information on how to clean your gear how to properly stow your store your gear or to adjust your gear check out the SSI equipment techniques program it's a great course to learn more in-depth techniques to take good care of your gear now I will state it's not a technician level course meaning you're not going to learn how to rebuild stuff but you will learn how to replace certain o-rings and to store it properly and clean it properly and even to adjust certain things on it it's a great class to check into guys if you got any questions on this please put it down in the comment section below if you want to know how I did two calculations just put it down the comments and I'll try to answer it the best I can I want to give a huge shout out to Steve Nash Steve I really appreciate you sharing your story with us we're definitely glad that you made it back safely from it and I appreciate you coming out and helping us out you know with this test here guys if you like the video simply hit that like button for me share it with all your diver buddies out there let them see this that way they understand just how important it is to take good care of their gear and just how dangerous a catastrophic failure can be at depth guys I really appreciate you watching the video check back each week for a new one as always make sure you follow us on Instagram and Twitter like us on Facebook pin us on Pinterest subscribe to us here on YouTube and as always guys we appreciate your business guys we really appreciate you watching our videos if you liked it make sure to give us a big thumbs up if you're not a subscriber simply hit that subscribe button for us and make sure you hit the little bell to turn on all notifications if you want to see some other cool videos make sure to click these links here they could be scuba tips they can be diving videos search-and-recovery videos or gear reviews once again guys we really appreciate it

Channel: undefined

Views: 16,919

Rating: 4.9003115 out of 5

Keywords: Lake Hickory Scuba Center And Marina, Instructor Bryan Stafford, What Is The Difference Between A Low Pressure And High Pressure Air Line, Catastophic Failures While Scuba Diving, Scuba Divers Running Out Of Air, Gas Calculations For Scuba Divers, Servicing Scuba Equipment

Id: rLr179pej4Q

Length: 16min 12sec (972 seconds)

Published: Sun Feb 04 2018