View Full Version : Reg Tuned/Detuned Crack Pressue

07-25-2007, 03:39
Silly question time--

Atomics B2's.
Looking at the invoices for me b2's. Couple of questions on these regs.

One the B2's is
Intermediate Pressure 145
Crack Pressure .6

One B2 =
Intermediate Pressure = 135
Crack pressure = 1.0

Does that mean that when detuned at surface they are .06 and 1.0?
and what would they be at depth by tuning the knob? Or does the knob even mess with that?

Then I have an octo that's at 1.5 and one at 2.3

So would I want both 2nd's at .6 or there-about? Or is that what the knob takes care of?


07-25-2007, 09:50
Usually that is at their best breathing. By turning the knob counterclockwise you you increase the spring pressure, thus increasing the breathing resistance. .6 is really easy, probably too much, the chance of free flow is pretty good. 1.0 is also really good, may be too easy also. The good thing is when they are that easy to breath you can always detune if needed; you cannot go the other way

07-25-2007, 09:52
Forgot to mention the octo's. They are always or almost always set harder to breath because they get stuck in weird places and have a tendency to freeflow. Since they are not used that often (hopefully) they are adjusted to breath harder.

ScubaToys Larry
07-25-2007, 10:17
Exactly correct. Besides, the way I look at the octo... if someone needs it, they are normally not that picky. If they don't like the reg, I seriously doubt they will just go somewhere else. smileys/smiley36.gif

07-25-2007, 10:28
The 145 psi IP is probably within spec but I would look for something lower on a new BP 1st. As it gets used, the IP is just going to get higher. I'd also watch that octo at 2.3" CP. That is a bit high but should drop as the seat takes a set. Check it's performance at depth to see that it is not uncomfortably difficult to breath.

07-25-2007, 10:35
Thanks Guys!

B2's are really easy to breath compared to some of those rentals I was playing with in the pool :).
The 1.0 with the knob turned Cntr-clockwise about 1/2, has not free flowed yet.
Other one has not even gotten wet yet-- :)

Now if I can get the Dr. to let me go get into the water again, I'll actually get to get some of these trinkets wet again.