Discuss: Safe to change inflator schrader valve fitting to high flow Air2/SS1 type fitting?

[Wiznutaggie]

So my query today is in reference to changing the Atomic AI inflator nipple from the standard schrader type to the high flow SS1 type. I had a recent exchange with an Atomic rep that went as such:

Me: My issue is the fitting that connects to the LP inflator hose. The AI inflator uses a standard inflator nipple, while the SS1 uses the higher flow nipple. To further streamline, it would be ideal if the AI inflator also uses the same higher flow nipple that the SS1 uses for connecting to the LP hose. The issue that I've found is that the threads on the AI inflator nipple aren't a standard 3/8-24 and I can't find a high flow nipple that will fit the AI inflator threads. Ideally I would be able to swap out the AI inflator and SS1 without having to change LP hose ends or using a high flow nipple to standard inflator nipple adapter.

Atomic: What you’re looking to do is not possible. All brands selling an integrated inflator/safe second are not compatible with a standard LPI fitting.

Me: Why not? The inflator mechanism is identical in the ss1/ai inflator.

Atomic: You’re trying to modify a life safety device to do something it is not designed to do. I can’t stop you from altering life support equipment, but I urge you not to put your life at risk for convenience. The SS1 is not engineered to use the LPI fitting as it will change the dynamics of breathing from the regulator at depth. And an LPI is not designed to take constant higher pressure from an SS1 hose without failing prematurely. I want to be very clear, what you are doing is unsafe and not authorized by Atomic Aquatics.

I feel like I'm getting the generic "don't mess with our stuff cuz liability" response. Thus... In reality is there an issue with putting a higher flow fitting on an Atomic AI inflator considering the internals are 100% identical to that of the SS1? The reps claim that the AI can't take constant higher pressures without failing prematurely is truly mind boggling, as intermediate pressure is going to be identical either way. The only difference will be a higher flow rate, but given that the internals of the AI and SS1 are otherwise identical, it should only change the flow rate to match that of the SS1. Am I missing something here in my thinking???? Does the reps claim hold water that it is dangerous?? I think not, but what do you think?

 

[happy-diver]

Logical doings are an anathema to current thinkings writings or speakings repeated until cemented into lore


But I do enjoy the control of the schraeder valve, inside my inflators, never having needed the blast of others
Even with negative entry, and diving heavy, and also racing to chosen depth, I have always been able to time
it and been able to stop my descent pretty much before the deck or shelf or bottom or not too far past them

 

[-JD-]

My guess is that your email was responded to by an office worker who likely has limited technical understanding. Yes, the inlet pressure is the same.

This is a US company and you are a US user, so the corporate (lawyer) party line is probably that Nobody but a factory-trained professional should ever use a tool on their products and nothing should ever be modified.

It sure looks like the internal parts are the same, but I guess it is possible that the spring rates are different - were you able to confirm that the part numbers are all the same?


The one fundamental difference that I could envision is that the SS1 has intentionally constricted air passages to throttle BC inflation given the higher-flow potential of the connector. The AI might have less constrained passages that are somehow matched to the lower-flow standard LPI connector.

You could test this pretty easily if you have an adapter that allows you to run the SS1 off of a standard LPI hose - time inflation 0-full for both. My gut is there will be little difference, but who knows ... [EDIT: for best available info, time 0-full with: SS1-HighFlow, SS1-StandardLPI, AI(StandardLPI)]

The fact that they are using an unusual thread for the AI does raise the question - is there a deliberate reason?

---

 

[lexvil]

I’m totally out of the loop on this inflator and so I went to Atomic and read the “blip” there is no reason for them not to offer that larger size fitting at least as an optional part and I find that more interesting since they claim that until they came along inflators were an “afterthought” and by not making it interchangeable with the SS1 hose fitting seems an non-thought.

The trick is to get to someone in the design department rather than the “brand” promotion department.

I’m more curious as to why they brought a $250 inflator to market in the first place.

 

[inquis]

Given the same IP, the force goes as the area of the seat, which might be higher in the high flow case. (I don't personally know.) I would check if the springs are the same.

 

[johndiver999]

This is only my guess, but the issue is the fitting on the hose, not the inflator itself. The SS1/Air 2 fitting on the hose is designed to provide a high flow rate - very similar to pneumatic hose for pneumatic tools.

Contrast that with the standard BC inflator which uses a schrader valve - same as used in a bike inner tube, is not intended to provide a similar high flow rate.

I think your idea that there should be one standard fitting for all BC's might make sense especially when you realize how much easier it is to disconnect an Air2 inflate hose underwater compared to a standard BC inflator. Sea quest played around with the fitting many years ago and created an even smaller one. It was not compatible and quickly went out of favor - it was even harder to manipulate.

If you want to keep one hose, just buy the SS1/Air2 hose/fitting and add on a $13 adapter from Dive gear express, and now you can plug into a standard inflator and a standard intermediate gauge and you can plug into a standard tire inflator adapter .so you can fill your tire on the way home from a dive if you save a little reserve.

I didn't know the adapter existed as an off the shelf product until a few weeks ago and immediate went out and bought two

 

[Endler's]

From a safety standpoint, wouldn't a higher flow fitting, be more of a danger in a runaway inflator situation?

 

[johndiver999]

From a safety standpoint, wouldn't a higher flow fitting, be more of a danger in a runaway inflator situation?

Not so much if you can disconnect it easily and quickly.

 

[Wiznutaggie]

It sure looks like the internal parts are the same, but I guess it is possible that the spring rates are different - were you able to confirm that the part numbers are all the same?

The one fundamental difference that I could envision is that the SS1 has intentionally constricted air passages to throttle BC inflation given the higher-flow potential of the connector. The AI might have less constrained passages that are somehow matched to the lower-flow standard LPI connector.

I haven't taken a look at part numbers, but the springs are visually identical and wouldn't affect the flow rate. It is hard to see in the second picture, but there is a small hole that is drilled between the valve and the inflation tube pathway. Identical size hole in both and a direct line, so there is no difference in internal constrtiction.

From a safety standpoint, wouldn't a higher flow fitting, be more of a danger in a runaway inflator situation?

Perhaps in a different inflator, but since the internal pathway and valve seat area are identical between the SS1 and AI, the flow rate should subsequently be identical if the inlet fitting is made the same. So unless the SS1 is considered a dangerously high inflation rate, then changing the AI inlet to the higher flow to match that of the SS1 should logically not be dangerous.

 

[dm9876]

The response from the rep sounds like they are confusing your intentions. They are describing what would happen if you put a low flow connection on the SS1 as I'm thinking that is what most people would be aiming to do.