Strong Purge/ Weak Purge...

[FyVe]

why is it that some regs. like Mares (my brothers V16 metal) and my old (to remain nameless) have a very mild purge, and some such as MK25 S600 from Scubapro have such a strong purge?
what causes that? is it tunning? or just how they are?
thanks

[ianr33]

It is due to the maximum flow rate through the first stage.Higher performance regs have a larger flow rate

[scubasavvy]

I used a titanium reg the other day...I forget what brand it was, but it almost knocked me on my arse.

[subsur]

i have poseidon xstream and i NEVER use the purge button underwater - it'll take your head off.

[DirtyWaterIL]

Originally Posted by subsur

i have poseidon xstream and i NEVER use the purge button underwater - it'll take your head off.

when a buddy of mine first passed me his poseidon under water for me to try it out i saw a little grin on his face and soon figured out why when i hit the purge button. Its nearly as strong as cracking a full tank valve.

[Black-Gorrilla]

so it's not really nessesary... but some just have enuff power to out do others? kind of like "because i can..."

[awap]

I really don't think it is a flow rate variable as much as a difference in the venturi effects. That is, it may just be harder to control the flow rate when you purge a 2nd that has high venturi effects. Do those with the higher purge flow also tend to provide positive pressure breathing?

[Black-Gorrilla]

wish i could answer that... the ones that i know purge hard for sure are scubapro's and Apeks (only ones i've seen)

[plot]

Avoid even using the purge if you can. Have enough air in you to purge by blowing out and you'll be alot better off.

Start purging lightly before you put the reg in your mouth and you can clear out most of the water without ever actually hitting the purge while it's in your mouth.


This doesn't really answer the question as to why some regs have strong/weak purges, but I wanted to bring it up becuase purging can be somewhat dangerous if you're not expecting it to blow you away or do almost nothing.

[ScubaToys Larry]

It's really not connected to the flow rate, the first stage, or high or low performance. It's a simple matter of how far they let the purge button go in. If you remove the cover from a mares abyss and hit the purge lever, it too will blast out a ton of air... same with the protons. But what is the purpose? You need enough air to evacuate a very small volume - so anything that blasts out enough air to fill a lift bag to float the titanic is just wasting air.

Some companies just set theirs up so when you hit it, a little air comes out... that's all. I would not let that affect me one way or the other on the decision between two regs. Absolutely a non-issue. As long as it gives enough air to clear the second stage - anything more than that is not necessary.

Not that one way is right or wrong - it's just a different philosophy in manufacturing design.