Thoughts on the safety of this?

[Franklink]

I've got about 60hrs on my Shoebox. Part of my system is a cheap filter (more of an oil separator than water removal, but that's another discussion).

I've been thinking for awhile that that little filter sees the full 0-4400 range of pressures EVERY time I fill tanks. I'm no metallurgist, but it seems like I read that part of the reason why airgunners arent too hard on tanks is because we live at the higher end of their pressure ranges MOST of the time. Something about increaseing the number of times the pressure vessel has to go from 0 to full pressure increases stresses on the metal, leading to premature failure.

If that little filter went boom I suspect it'd be like a grenade.

For $20 I think I'll go ahead and buy a new one and toss the old one. But I'm still curious what the engineers (and smarter than myself) among us have to say about this. Danger? or not?

[Doug Wall]

It's safe, but it's probably doing almost nothing for moisture removal. If you're filling tanks, you should at least have one of the big desiccant cylinders.
https://www.ebay.com/itm/4500psi-PCP-Air-Compressor-High-Pressure-Filter-Water-Oil-Separator-Scuba-300Bar/313267820763?hash=item48f03798db:g:UtYAAOSwNZJfkQdG

[Sfttailrdr46]

I agree and the large filters work well I installed one on the output HP side of my Yung Heng compressor and so far no problems .

[AlanMcD]

I use a similar one (maybe a bit smaller) on the output side of my Shoebox, but not for managing any moisture - I use it to make sure no lubes or other contaminents get into the fill whip hose on my tank.  I used to not worry about it as I always vented the air line using the Shoebox vent, but I have swithced to doing the really high pressure part of the venting with the tank vent to save the wear and tear on the Shoebox (as others have suggested in other posts).

I have no concerns about the main body of the filter - the material thickness and threads on mine appear to be more than adequate for the loads.  If I have any concerns it is with the fittings - many of the Chinese ones are not the most robust.  If I were to replace it out of caution, that would be my reason for doing so, but I think it is fine for a few years of use.  I will say I was VERY cautious when I loaded mine up for the first time to see if it would hold together, and I have no means of testing the materials in the one I have (let alone yours - these all come from different companies over there), so I am just working off an educated guess.  I have thought about getting a higher quality female fitting for it, but have not done anything about it.

If you want to trap moisture with a Shoebox compressor, the best way to do it is on the input side - use a large desiccant filter on the air before it goes in, and there will be no condensation to trap on the output side.  Once water vapor is removed from the air going into the compressor, it is gone because it is a closed system.  So if we remove enough water vapor such that the dew point of the air going into the Shoebox is low enough, there will be no condensation occurring, or even enough remaining water vapor in the air to catch in a post compression desiccant.  Once is enough, no matter how many seem to want to do it twice.  There are lots of posts on the best ways to do this . . .