09/29/2023
Do you want a full cylinder, or will 90% do?
When it comes to making sure our cylinder is full at 4500 or 5500 PSI, it is important to know how much time we can get out of that final 500 PSI.
The amount of breaths we get out of 500 PSI is important, but knowing how much time we get out of 500 PSI should be the goal.
We know that after physically pushing ourselves in training we can get 15 breaths out of 100 PSI.
So 500 PSI = 75 breaths. Through training, we learned we can bring our breathing down to 4 times a minute after one minute of working to control our breathing. 5-second inhale, hold for 5 seconds, and then exhale for 5 seconds. Using the breathing technique that works best for us, we get to 4 breaths per minute.
Now that we’re at 4 breaths per minute, we look at the 75 breaths we get out of 500 PSI. We are now at 17:30, in theory for 500 PSI. That’s a lot of time.
After testing it several times we found we can last between 15 and 17 minutes on 500 PSI. This takes into account the one minute of getting our breathing under control to get to 4 breaths per minute.
It’s important to physically push yourself in full gear to that final 500 PSI cylinder pressure to get realistic times in training. Just draining your cylinder to 500 PSI and then applying the techniques won’t give us a realistic time.
Also, we have to consider that our sympathetic nervous system isn’t in play based on the uncertainty and fear associated with being at 500 PSI in an actual bad spot.
The 500 PSI is used to support filling our cylinders all the way.
It demonstrates how much time 500 PSI could provide if needed.
Per NFPA 1852 6.3.7.1 we should fill our cylinders when they drop below 90% of full.
That was 4050 PSI with 4500 PSI cylinders and 4950 PSI with 5500 PSI cylinders.
With that being said we will always use a full cylinder, knowing the why behind the reason.
We don’t want to do anything 90%.
