Confused about high pressure hose and low pressure hose failures

[Bert van den Berg]

I read somewhere that if your high pressure hose failed it might empty your tank in 20 minutes but if your low pressure hose failed you might only have 2 minutes. This seems counter-intuitive. I would have thought that a high pressure hose failure would be a bigger problem. Could it be that the high pressure hoses have a very small inside diameter that restricts the air flow?

Regards,

Bert

 

[rivers]

if you take the hoses off your first stage, you'll see the size of the hole on the HP is only about the size of pin prick, where as the low pressure ports have much larger holes in comparison

 

[kwinter]

Could it be that the high pressure hoses have a very small inside diameter that restricts the air flow?

Yes, exactly.

 

[Pedro Burrito]

http://www.scubaboard.com/forums/ba...-drain-80-cubic-foot-cylinder-4-failures.html

 

[ptbodiver]

Had a high pressure hose fail recently in Cozumel. Failed in first 10 minutes of dive. Completed a 45 minute dive at an average depth of 50ft with a 3 minute safety stop. Finished with 500 psi of an AL80.

 

[scubadiver888]

As everyone has noted, the HP line is a very small diameter passage. So it takes a lot longer to drain the tank through the HP line than through the LP line.

You might also enjoy the following video: https://www.youtube.com/watch?v=2-dhP_jSO6I. It shows them actually cutting the different hoses to see what happens.

 

[Steve_C]

All the high pressure line has to do is get the pressure to your SPG. So there is almost no flow. Low pressure lines have to actually do things so they are much larger.

 

[Bert van den Berg]

Hi scubadiver888. That's a great video - very funny but informative.

Cheers,

Bert

 

[swimmer_spe]

one other thing you might actually have happen is that the hose gets frozen over, and then you have less of a problem.