DIY coalescor advice?

[markbruscke]

Looking to build a coalescor. Have studied what exists on SB and tDS; didn't find much in the way of design ideas, parts recommendations. Seems to me the HP vessel could be made from XXH stainless steel pipe with plugs pinned or clamped (with 4 bolts, a la a booster). Anyone have any success with such a design; or any alternatives?
Also looking for input on coalescor elements; design choices, sources, part numbers. L-F has a good article titled "Coalesing" in it's Documents page; but no design details.
Once I get a coalescor working I'm planning on adding a vapor absorption and filter stack. (I have a RIX so water is my first concern, filtering is just to tidy up.)
Thanks,
Mark

 

[pescador775]

Actually, filtering involving adsorption of moisture is a primary concern of oilless and oil lubed compressors, at least it is today after the CGA amended the CGA G-7 for Grade E air. The requirements are the same for moisture regardless of type of compressor. It just so happens that the techniques used to remove moisture also reduce oil vapor, congruent effects.

I don't know who publishes specs for home made coalescers. This is a realm of custom work involving controversy regards materials, quality of machining, arcane matters of stress crack propagation, cycling, calculation of burst pressure, etc. Then there are the advocates of KISS with their bolts, commercial steel pipe and external caps versus the folks who cut internal threads and machine threaded caps, all of aluminum which is a subject in itself. Some use 6061 to a 2.5 safety standard and others use 7075 to a 4.0 std. Then there is the exotic 7032 Al which is out there somewhere. All the while, the stainless steel advocates search for the right alloy. It's there but nobody's talking, not yet anyway. Maybe you can tell us.

 

[oxyhacker]

Easiest way to make a DIY coalescor is by making/obtaining a suitable high pressure vessel, then putting the guts from a cheap low pressure separator into it, so you end up with a proper sintered element and little whirrly-thingee rather than just a tube with some holes in it like cheap HP compressors use.

How much pressure you want to be able to handle is important. Seamless SS schedule 80 pipe and surplus accumulators are good up to 3000 - maybe 3500 psi, but above that become questionable.

Shelden Sporting Goods has some good low price alternatives made with surplus parts, well worth looking at.

 

[pescador775]

Creativity can substitute for a lot of sweat. Last year, I bought an EBay special. I think I was the only one to bid, $100 for a NOS, Bauer steel coalescer, relief valve and BP valve. You all remember the type, Bauer used them until the 1980's. I removed the simple internals and packed the thing full of filter media. Just right for a portable compressor. The plated steel walls of the shell are 1/4 inch thick. I estimate burst press at 20,000 psi. One bonus, the cap positions are adjustable, it revolves so the fittings on the bottom and the whip (on top) can be adjusted to just about any angle. The relief valve alone is more costly than the final price.

 

[frogman62]

Mark, I believe I have a solution for your problem. I have designed fitting and repackable filter cartridges to fit York Hydraulic accumulators. These have been destructive tested to pressures over 16000psi. Using two of these units you can have very dry and Grade E breathing air for less than $300 including a back pressure valve which will increase moisture absorption.
These are shown on my web site toward the bottom of the site.
sheldensportinggoods.com
Frogman62
jim shelden
316-992-0505

 

[captndale]

I once made a filter cartridge out of a high pressure hydraulic cylinder. It consisted of a steel tube with thick aluminum end caps held together with four steel tie rods. It worked well for a long time - untill one day the tie rods failed. The top end cap went through the ceiling and there was filter media all over the place. The ruptured hose that had been attached to the cap flailed around breaking things untill the storage bottles were empty. Fortunately, no one was injured. That ended my career designing or building my own high pressure pneumatic components.

 

[frogman62]

Capt. Dale, I understand you concern.
What I have done has not modified any component of a new Hydraulic cylinder.
Two of the original 60 in the lot were destructively tested to pressure of over 16,000 psi. I have used new hydraulic fittings and designed an adapter inside the cylinder to accept a repackable cartridge or a Lawrence Factor cartridge. These cylinders are not a rework- they are new unused cylinders. I have not been in this business for over 40 years to make a stupid mistake on some jury rigged equipment.
Jim Shelden

 

[captain]

I don't know how many small compressors have separators/ coalescers after each stage but I have found having one after each stage works better than one final. The first stage traps about 75% of the water, the second about 15% and the final gets the rest before the drying tower. It also seems help the compressor by less water blow by to the oil and residual water in the cylinders after shut down.

 

[frogman62]

NAVED, I like your picture -- that looks like an Aquamaster regulator and vest that I used when I started diving in the late 60's and also used at the UWSS in Keywest in 1962 Yes/No
Jim Shelden

 

[captain]

NAVED, I like your picture -- that looks like an Aquamaster regulator and vest that I used when I started diving in the late 60's and also used at the UWSS in Keywest in 1962 Yes/No
Jim Shelden

Regulator is either an Aqua Master or Mistrial, don't recall what I was using when the picture was taken, I have 6 double hosers that I use. The vest is a Seatec, that is still available.

NAVED is National Association of Vintage Equipment Divers, Captain is my user name.