Fellows FWIW, I recently ordered an OSEL ALVBOV and received it in a reasonable amount of time. I therefore do not doubt the OSEL spec Apollo 1st stages they sell are as they claim to be, since they are much easier to bring to market than a brand new part such as the ALVBOV.
SR, Just to correct a minor point that you have alluded to. In that 1st stages were not necessarily easier to bring to market than an ultra-low WOB BOV. With the requirement for the 1st stages to be CE'd for 300bar oxygen use, this required significant in time and resources testing at bam.de in Germany. Not to mention a lot of explosively by fire destroyed 1st stages until the right combination of lube being Gleitmo 599 and HP seat material was determined. Whilst rebreather fires are limited, they are still a risk, that this work minimises.
The backup if the Apollo 1st stages failed was Apeks DS4s and both are CE'd for OSELs units per their testing but the Apollo 1st stages were just found to be a better engineered product, and still to this day the best available, with cost being irrelevant.
http://www.deeplife.co.uk/or_files/DV_DL_ALVBOV_Breathing_Params_A3_100318.pdf
Despite the PR failings of OSEL, I have had many good conversations/correspondence with them, and it seems to me that from the basic WOB specifications for CC and OC, the ALVBOV is the best BOV, if your gas flow goes the right direction. Big if, since it is opposite the current standard direction. It may be the best thing to come from the APOC design, and obviously they would sell a lot more if the gas flow was reversible. And I’m not even a fan of the automatic bailout function built into the ALVBOV, though I have not tested it yet, as I’m not through making the necessary modifications to my Prism 1 CLs to adapt to the supplied OSEL CL elbows
In addition to selling the DL designed Functionally Safe rebreathers, one of the reasons OSEL was set up was to support homebuilders and assist small scale manufacturers by offering professionally engineered components and sub-assemblies with the R&D and certification costs covered.
With that in mind, what is the flow orientation of the Fathom and bore size of the reinforcing rings molded into the FMCLs?
As I note it is currently supplied with a GG BOV and a factory upgrade with OSELs ALVBOV would significantly reduce the Fathom's overall WOB. If this is desired. It would also remove the need for a separate ADV and MAV.
Will post my actual dive experiences in another thread but having one in my hands, I really like the design, basic functionality and build quality of the ALVBOV.
Thanks SR. It's always good seeing warts and all reports from users. Some feedback is subjective and if the issue is a Functional Safety design requirement there is not much we can do about offering a better product that suits the individual but all feedback is noted and reviewed.
Question, if someone kills themselves with an OSEL piece of kit, does Deas testify against himself?
An interesting question noting Alex's expertise could just as easily be hired by the defense in the couple of cases he has been involved in to date. For some reason however none have wanted him to prove their units didn't have design defects and met the standards they were certified to, if so. With the multiple fatalites for the same root cause on certain units this is probably understandable. Note Case 1-10 in particular
https://www.diversalertnetwork.org/medical/report/AnnualDivingReport-2018Edition.pdf
As there has not yet been a fatality on any DL designed rebreather across their Functionally Safe certified commercial, military and recreational units despite >10 years of use; you have raised a very interesting question. Which is also why DL don't yet report one in their accident list; however, it is a simple statistic that this will unfortunately alter at some point in the future. OSEL will then to the best of our ability for the rebreathers or components we have manufactured provide support to the divers NoK and provide direction/resources to enable independent inspection and testing of the units fitness for diving, ensuring chain of custody and evidence documentation is maintained. Backed up by provision of all of the relevant certification testing and documentation inclusive of FMECA and design validation testing etc etc. As a requirement of the Functional Safety certification all details of the fatality and investigation would then be documented in DLs accident list at
Deep Life Design Team: databases and analysis of rebreather accident data