algal bloom
Contributor
No one here knows me because I usually like to sit back and read. I had a situation this weekend and a conversation later that made me want to post and see if those with more knowledge could explain. I'm sure this topic has been done but I couldn't find my specific concerns.
The situation: I'm embarassed about this but here is what happened. I was doing some search and recovery this weekend using a reel with a rope and swimming circles around a stationary buddy at a depth of about 40 ft. It was a very tiring, air consuming dive. After the actual search pattern, my buddy reeled me in, but he was a little tangled so we stopped to untangle him. One thing led to another and I ended up with 150 psi at my safety stop (15 ft). I breathed off of my buddy's octo for the safety stop and we then made a safe ascent. Ending with so little pressure was truly a rookie mistake and I am in no way trying to justify it.
The conversation: A friend later told me that I may have caused water to back up in to my regulator low pressure lines and possibly even my tank. We got in to the physics a little but his rationale and mine were not meshing. Dive shops have since told me not to worry, but why would there have been a worry at all?
What my question really boils down to is just my lack of understanding of the way my first stage regulator works. It is my understanding that my first stage drops tank pressure down to about 140psi. The second then drops the first stage pressure down to ambient pressure. I'll just use 33 ft as my example depth. I know that theoretically the absolute pressure acting on my body and everything else should be about 29.4 psi. So as far as the tank goes, I don't see how the 29.4 psi ambient go against the flow if my 150 psi tank air. It seems like there should be no leakage in the tank. It seems like the same would be the case with my low pressure lines where 14.7 psi g is acting against my 140 psi g on my low pressure lines. However, I'm wanting to know what happens if your first stage drops tank pressure to 140 psi but the tank pressure is below, that say (110psi). Can anyone explain this? Also, can anyone explain the danger of water backing up into my low pressure lines? Thanks!
The situation: I'm embarassed about this but here is what happened. I was doing some search and recovery this weekend using a reel with a rope and swimming circles around a stationary buddy at a depth of about 40 ft. It was a very tiring, air consuming dive. After the actual search pattern, my buddy reeled me in, but he was a little tangled so we stopped to untangle him. One thing led to another and I ended up with 150 psi at my safety stop (15 ft). I breathed off of my buddy's octo for the safety stop and we then made a safe ascent. Ending with so little pressure was truly a rookie mistake and I am in no way trying to justify it.
The conversation: A friend later told me that I may have caused water to back up in to my regulator low pressure lines and possibly even my tank. We got in to the physics a little but his rationale and mine were not meshing. Dive shops have since told me not to worry, but why would there have been a worry at all?
What my question really boils down to is just my lack of understanding of the way my first stage regulator works. It is my understanding that my first stage drops tank pressure down to about 140psi. The second then drops the first stage pressure down to ambient pressure. I'll just use 33 ft as my example depth. I know that theoretically the absolute pressure acting on my body and everything else should be about 29.4 psi. So as far as the tank goes, I don't see how the 29.4 psi ambient go against the flow if my 150 psi tank air. It seems like there should be no leakage in the tank. It seems like the same would be the case with my low pressure lines where 14.7 psi g is acting against my 140 psi g on my low pressure lines. However, I'm wanting to know what happens if your first stage drops tank pressure to 140 psi but the tank pressure is below, that say (110psi). Can anyone explain this? Also, can anyone explain the danger of water backing up into my low pressure lines? Thanks!
!
ScubaRon
