Question Box clamp pressure?

[Sensorone]

My Phoenix DA Aquamaster breathed wet offshore last week, and when I got it apart there was salt water (<1oz) in the second stage can. Not enough clamp pressure? Performance otherwise was great. Using a stainless clamp ring but was not tightened completely as I was concerned about damaging the silicone diaphragm. Thoughts?

 

[Scuba Lawyer]

I have never damaged a main diaphragm in a two-hoser by overly tightening the clamp ring. I have had H2O enter the cans because my ring was too loose. Also look at the mushroom valve on the intake side of your mouthpiece, the hose clamp holding the inhalation hose to the horn, the hose clamp holding the inhalation hose to your mouthpiece, the inhalation hose itself, and the main diaphragm to make sure no nicks, cuts, debris, looseness, etc... There are many points of water entry possible on DH reg. Just go through the possibilities and rule out one by one. My 2psi. Good luck!

 

[Luis H]

I completely agree with the post from @Scuba Lawyer.

In addition to the inspections, do a vacuum test and see if it holds. Just make sure the dust cap is on or attached to a tank valve (with the valve closed) and see if will holds a vacuum.

You can tighten the diaphragm without damaging it, just as @Scuba Lawyer said, but be aware that if you tighten it too far, it does affect the breathing performance of the regulator. I have tested this many times and it is very repeatable. I have checked on several metal cans, all of them using the band clamp (I never use the old clips).

I use a Magnehelic gauge to measure the cracking effort and I have found that that the cracking effort will increase if I "over-tighten" the band clamp and it will go back down when I loosen it just a bit. The sweet spot seems to be when I tighten it just enough that I can grab the horns by hand and they will not slip when I try to rotate them (that is also enough for a good seal). You can go a bit beyond that point, but I don't recommend going too much more. Tightening beyond that point will not do any permanent harm, but it doesn't help sealing any better and the breathing performance is affected. You may not notice it much, but it can be measured and I have repeated the measurement many times.

Good luck.

 

[Sensorone]

Thanks for the info. Was a dry breather in the shallow lake but wet offshore in 80ft or so. Will do as you say with the magnahelic. Must have been just slightly loose and at depth got a little intrusion of water. Was never anything real concerning. Rinsed out thoroughly and all seems fine. Should I worry about the salt water getting into the can? Do I need to break down the first and second stage for an inspection? Was a small amount of saltwater left in the can post dive but I was having to clear the loop several times during a dive. I'm sure it was do to insufficient clamp pressure but want to make sure I don't need to go further into the reg to verify cleanliness. I don't see how any salt water could get upstream, but it has me wondering. Want to take the best of care of my Phoenix. Thanks again.

 

[Luis H]

A little salt water into the can is not a big deal. From a mechanism point of view, it is the same as saltwater in the second stage of a single hose. It happens on every dive in the case of a single hose.

It is very common after a week of diving that I find a tiny bit of water in the can. The mouth-piece valve is the most likely source. They are not perfect. With the use of the DSV I have reduced that "moisture", so it rarely happens.

Just rinse the inside of the can and dry it before closing it back-up.

The depth would not make any difference if you have a small leak. The pressure differential is always the same at any depth.

Good luck

 

[Sensorone]

Copy all. Thanks for the help.

 

[John C. Ratliff]

My only input is that when you do the leak check by inhaling on the dust capped regulator, that the dust cap has an O-ring in it (that’s where the spare O-ring usually resides).

SeaRat

 

[Sensorone]

Roger that.

 

[Sensorone]

On

A little salt water into the can is not a big deal. From a mechanism point of view, it is the same as saltwater in the second stage of a single hose. It happens on every dive in the case of a single hose.

It is very common after a week of diving that I find a tiny bit of water in the can. The mouth-piece valve is the most likely source. They are not perfect. With the use of the DSV I have reduced that "moisture", so it rarely happens.

Just rinse the inside of the can and dry it before closing it back-up.

The depth would not make any difference if you have a small leak. The pressure differential is always the same at any depth.

Good luck

One thing I did find is that the DBE was in the process of coming unbonded from the can, but was still attached and performing fine but just barely. I normally put a dollop of adhesive under the DBE in addition to the the intake area. The bead of adhesive was kind of thin IMO. Easily fixed.

 

[captain]

Or small crack in the inhalation hose, check between all the convolutions, likely where the hose hits the edge of the inhalation horn.