The Aqualung ABS and many others like it employ a fixed orifice and a standard downstream poppet to provide reliable, if uninspiring performance. Many are touted for their small form factor and ability to be utilized "upside down" when handed off in an OOA emergency.
What to do when you are presented with one that has not seen service in many moons?
If you try to unscrew the outer half of the valve body using the case to hold the inner half, this frozen valve half will likely turn inside the case, distorting it permanently!
From this point on, the valve may not be held straight, and changing hoses will likely result in a cocked valve, asymmetric lever, and degraded performance in an already marginal second stage.
Bruce Howe at ScubaTools.com created a wonderful new tool ($17) introduced at DEMA this past November to address this challenge. It's called a 2nd Stage Valve Body Internal Retaining Nut Tool
SKU: 20-228-100
The feet of the tool are designed to fit in the groove occupied by the lever, enabling you to hold it steady while unscrewing the outer half, without damaging the case.
That said, I've run into some problems with the Aqualung ABS. Those issues may apply to other regs, as the tool is listed for more than a dozen models and brands.
First off, the feet that slip into the groove where the lever runs are slightly too thick.
It was a quick matter with a grinder to thin them down <1mm.
As you can see, there's a very helpful recess machined into the tool to accept the stem of the poppet, so that you can disassemble the valve assembly once you've unscrewed the nut and flipped out the lever. The tool does an excellent job of holding the inner half steady while you apply the substantial force required to unfreeze a green valve.
However, upon reassembly, torquing the halves tight without similarly stressing the case is not possible because of the nut, which now displaces the feet outside the inner half.
So my next mod was to Dremel a recess in the other end (after thinning the feet as above) so that the tool would fit around the assembled valve for torquing.
At this point, the next challenge revealed itself: the curved lever, even when fully depressed, got in the way of engaging the feet. So I ground a bevel in the back side to accommodate the lever:
...and bingo! The tool fit perfectly for torquing upon final assembly:
Torquing became a simple matter of mounting the tool in a vise.
What to do when you are presented with one that has not seen service in many moons?
If you try to unscrew the outer half of the valve body using the case to hold the inner half, this frozen valve half will likely turn inside the case, distorting it permanently!
From this point on, the valve may not be held straight, and changing hoses will likely result in a cocked valve, asymmetric lever, and degraded performance in an already marginal second stage.
Bruce Howe at ScubaTools.com created a wonderful new tool ($17) introduced at DEMA this past November to address this challenge. It's called a 2nd Stage Valve Body Internal Retaining Nut Tool
SKU: 20-228-100
The feet of the tool are designed to fit in the groove occupied by the lever, enabling you to hold it steady while unscrewing the outer half, without damaging the case.
That said, I've run into some problems with the Aqualung ABS. Those issues may apply to other regs, as the tool is listed for more than a dozen models and brands.
First off, the feet that slip into the groove where the lever runs are slightly too thick.
It was a quick matter with a grinder to thin them down <1mm.
As you can see, there's a very helpful recess machined into the tool to accept the stem of the poppet, so that you can disassemble the valve assembly once you've unscrewed the nut and flipped out the lever. The tool does an excellent job of holding the inner half steady while you apply the substantial force required to unfreeze a green valve.
However, upon reassembly, torquing the halves tight without similarly stressing the case is not possible because of the nut, which now displaces the feet outside the inner half.
So my next mod was to Dremel a recess in the other end (after thinning the feet as above) so that the tool would fit around the assembled valve for torquing.
At this point, the next challenge revealed itself: the curved lever, even when fully depressed, got in the way of engaging the feet. So I ground a bevel in the back side to accommodate the lever:
...and bingo! The tool fit perfectly for torquing upon final assembly:
Torquing became a simple matter of mounting the tool in a vise.