RIX SA-6 Moisture Separator and Filtration

[mgkarl]

I recently bought a used RIX SA-6 and I am in the process of setting up a home fill station. Initially I will be using it for high pressure air fills in my steel tanks, but eventually I would like to be able to produce OCA for partial pressure blending. The RIX just has the two small interstage separators that came standard, with a backpressure valve, and no other filtration.

For the initial stage of the project, straight air fills, I know that I need to add additional separation/ drying to avoid rusting my tanks. Should I just add an additional last stage separator, or do I need to also add a desiccant and additional filtration? For this initial stage I am looking for grade E air, dry enough to avoid rusting tanks. The RIX is oilless but it does use a gasoline engine, so having hopcalite for CO conversion probably makes sense even in this first stage.

Once I start doing blending, what additional filtration/ hyperfiltration do I need to add? This is just a personal setup, for myself and maybe one or two others, so I am not looking for a high flow commercial setup. Any advice on setting up the filtration system and recommendations on equipment and parts suppliers would be really helpful. Thanks.

[oxyhacker]

Mechanical separators can only remove a percentage (typically 80 to 95%) of the liquid water in the air - droplets and aerosols - and do not remove any of the gaseous water vapor which is dissolved in the air (and the air will always totally saturated with vapor when it enters the stacks). So mechanical separators alone, even multiple ones, cannot do an adequate job of drying air, making a media stack containing dessicants, which can adsorb both liquid and gaseous water, pretty much a necessity even with a Rix (unless perhaps you are doing all your diving in hot climates with aluminum tanks). ( So you are almost certainly going to have to add a media stack. They sell for $500 to 1000 new, though used ones turn up occasionally for about half that, and some DIYers have made them from surplus hydraulic accumulators or seamless SS pipe.

As far as partial pressure mixing, while most of the tech agencies have traditionally insisted that an additional "hyper" filter ( basically just a second media stack) is necessary to produce air clean enough for PP mixing, a lot of mixers feel that Grade E air is adequate and don't bother with a hyper filter. However, if you decide not to go with a hyper filter you should be fastidious in maintaining your filteration system.

I recently bought a used RIX SA-6 and I am in the process of setting up a home fill station. Initially I will be using it for high pressure air fills in my steel tanks, but eventually I would like to be able to produce OCA for partial pressure blending. The RIX just has the two small interstage separators that came standard, with a backpressure valve, and no other filtration.

For the initial stage of the project, straight air fills, I know that I need to add additional separation/ drying to avoid rusting my tanks. Should I just add an additional last stage separator, or do I need to also add a desiccant and additional filtration? For this initial stage I am looking for grade E air, dry enough to avoid rusting tanks. The RIX is oilless but it does use a gasoline engine, so having hopcalite for CO conversion probably makes sense even in this first stage.

Once I start doing blending, what additional filtration/ hyperfiltration do I need to add? This is just a personal setup, for myself and maybe one or two others, so I am not looking for a high flow commercial setup. Any advice on setting up the filtration system and recommendations on equipment and parts suppliers would be really helpful. Thanks.