what does the purge buttton in a scuba purge, water or exhaust?

Question

why is it important to purge always prior to taking the first breath?

Answer 1

-The purge button on the second stage of the regulator (the first stage is the one connected to the valve of the cylinder) has the function,when pressed,to blow out the water from the second stage,allowing you to breath the air that can flows in it.
-The other system to clean the second stage from water ( if your lungs are filled with air) is to blow air in it,before to try to breath.

Both the systems are valid,while you are diving,in order to purge the second stage.
Note :when the mouth piece of it is not in your mouth,water enters from there in the second stage.
-Pressing the button,or blowing out air in it,from your lungs,creates the opening of a valve on the base of the second stage, and the exit of the water from there.
At that point you can breath safely.
When you exale air , it will escape from the second stage from the same very valve.

-Another use of this button ,is to allow you to check (pressing it) if the valve of the air is opened and the device functioning. But the best test,is to have the mouth piece in the mouth,and trying to breath.The air should flow in your mouth without efforts.

Answer 2

The main reason to purge are to remove any water or dirt from the reg, the reason they teach to purge is that most people forget that there is water in the reg and instead of blowing out first, which would remove the water new divers often breathe in first and get a mouthful of water.
It is a good habit to get into for the simple reason that if you have an out of air emergency and grab your buddys octo which hasnt been used in who knows how long and inhale first without purging you will probably be inhaling water, soil , dirt , sealife or who knows what in to your lungs and that is the last thing you need when you are already out of air.
Doing a purge first will also check to see if the air is on( but this can be tricky because the tank could have been turned back off leaving only a couple of inhales in the line), and also you can make sure that the purge is indeed working, check for a free flow issue and that the reg is in working order.

Answer 3

There are two potential purges you could be talking about.

One purge is on your BC (buoyancy compensator). It releases the air from the bladder within it. You also have the capability to put air into the BC.

You don't necessarily have to purge before taking your first breath. But typically you have your BC full of air as you swim out to your dive site so that it helps you float. After that, you let the air out so that you are able to sink underwater.

What is important is that you have the correct amount of air in the BC such that when you are underwater you remain neutrally buoyant, meaning that you neither float nor sink as you are diving. This enables you to "hover" over reefs without bumping into them and allows you to swim in a level line while you are diving.

The second one is on the regulator. Generally this one you will want to use before you take a breath and descend. It forces air through the regulator to wash out any water that may be in the mouthpiece. You want to do this for two reasons--the first is so that you don't breathe in any water. The second is so that you can ensure that the air in your tank is turned on and the regulator is functioning properly.

Answer 4

I'm only an amatuer diver but i think it takes the water out of the regulater, so the reason you press the purge button is obvious, you don't want to get a lungful of water on your first breath...

Answer 5

to purge means to rid of whatever is impure or undesirable; cleanse; purify.
I've never done scuba, but I would assume that it cleans out the lines or gets rid of the water in the lines or something