oxyhacker:
Re aluminum, yes it can be used safely, but if Bauer and Mako and several others cannot make aluminum stacks that don't fatigue and occasionally let go (or at least stress crack), or have to be severely limited in cycles, what chance does a DIYer have? Remember they don't only design the things and hope they've though of everything, , but also test the design extensively before putting it into production. A DIYer doesn't have this luxury an basically gives it his best shot and then keeps his fingers crossed.
If alu is to be used, I think a Bauer style setup where an O-ringed plug goes into the tube and is held on by an externally threaded collar is preferrable to the a stepped plug that fits inside and is retained by internal threading - less reduction of the tube diameter, less steps to act as stress risers and external threading is always easier than internal for the amateur.
SS is hard to work, yes. So the secret is a design that requires the least workng possible. Cross bolted O-ring sealed plugs are probably the easiest way, though you have to keep the diameter fairly small to avoid overloading the bolts, though plugs retained by a collar can also be done with a minimum of machining. You wouldn't want to do this with alu, since the cross bolts would likely overstess it.
(Those Groban accumulators are starting to look pretty good even with postage)
I apologise for my absence from the discussion. Unfortunately my computer crashed as I was trying to reply to the above post.
My original question was whether or not any one had any personal experience of building filters. I asked this because I wanted to have sufficient depth of information to be able to come to an informed and considered decision on how best to expand the filtration capabilities of my system.
Before posting I spent several days searching the web and it became apparent that there was very little information publicly available on the subject. Being an extremely cautious person with a minimal understanding of suitable materials, construction methods, etc. etc. it seemed a little too Darwinian to attempt such a potentially lethal project from scratch when it was almost certain that there were in existence proven and tested DIY designs.
Imagine my surprise, I hadnt expected to be told on a DIY forum that I wasnt serious, neither had I expected to be told that I should buy them ?.
Previous research had led me to the conclusion that due to the high temperature and humidity of the area I needed to add between four and six towers, depending on size and final layout, to the factory provided equipment. Im sure that when one considers a cost of $800 to $1500 each the attractiveness of a self build option requires no explanation.
From reading Vances publications and posts I was leaning heavily towards the notion that the easiest and safest solution was to use accumulators but I still wanted to evaluate the feasibility of alternative ideas. This was mainly due to the fact that despite aircraft parts being unavailable locally there was an abundance of oil industry paraphernalia to be had if one was prepared to search for and identify it. Again, the attraction of locally sourced materials requires little explanation and when coupled with the abundance of machine shops the subject proved worthy of further investigation. In fact just after posting I located some extremely robust SS piping that had already been machined internally and that looked ideal for the project.
So being an extremely cautious individual in need of some hands on experience and knowledge prior to making a decision I felt that this forum would offer me access to some very knowledgeable individuals which it has.
Vance hit the nail squarely on the head when he drew every ones attention back to the focus of my question, which was a DIY solution in the spirit of a straightforward, safe design that eliminated any safety concerns.
And as he summarized the accumulators appear to be the most straight forward way to proceed and recently Ive been able to track some down at a very reasonable price, albeit in the US. Im currently waiting for the vendor to send me a few more details on the spec and then I should be all set.
The information put forward by all contributors, both on and off line, has been most useful and I thank you all for taking the time to answer my questions to date.
