UaVaj
Contributor
Partial pressure blending (pure oxygen is first put into the tank then topped off with air).
Let me elaborate. Let's start with a tank that has been O2 cleaned. Currently has 36% nitrox. By filling it first with pure oxygen. The mixture's percentage will increase possibly above 40% into the caution/danger zone. Then hydrocarbon free air is topped off to bring the mixture back down to 36%.
This could be a stupid question. However I would like to be educated for whatever it is worth. So here it goes.
For recreational purposes. Why even run the risk of making the mixture go above 40% during a fill? What is wrong with filling a tank with air first then topping it with pure oxygen?
Let me elaborate. Let's start with a tank that has been O2 cleaned. Currently has 36% nitrox. First fill it with hydrocarbon free air. That will drop the mixture percentage to somewhere below 36%. Next top it off with pure oxygen to bring the mixture back to 36%.
This way the mixture inside the tank will never reach 40%. Isn't this safer?
Why are PPB LDS choosing the "O2 first then air" method? I am all ears.
Let me elaborate. Let's start with a tank that has been O2 cleaned. Currently has 36% nitrox. By filling it first with pure oxygen. The mixture's percentage will increase possibly above 40% into the caution/danger zone. Then hydrocarbon free air is topped off to bring the mixture back down to 36%.
This could be a stupid question. However I would like to be educated for whatever it is worth. So here it goes.
For recreational purposes. Why even run the risk of making the mixture go above 40% during a fill? What is wrong with filling a tank with air first then topping it with pure oxygen?
Let me elaborate. Let's start with a tank that has been O2 cleaned. Currently has 36% nitrox. First fill it with hydrocarbon free air. That will drop the mixture percentage to somewhere below 36%. Next top it off with pure oxygen to bring the mixture back to 36%.
This way the mixture inside the tank will never reach 40%. Isn't this safer?
Why are PPB LDS choosing the "O2 first then air" method? I am all ears.