Aero Sub Compressor Plus 6000

[time2dive]

I am in the process of getting an Aero Sub Compressor 6000 Plus. Anyone know anything about this compressor?

I am getting 6 tanks (4 which are usable) a couple of regulators and old computers. An OLD BCD and a White Stag Horse Collar all for $200

[scubasteve59]

Hi,

Post a couple of pics showing compressor and data plates. If I'm right yours is a portable gas engine job? Did the $200 include the compressor? Wow!

[time2dive]

I finally got my compressor up and running. I had to have the gas engine worked on and I had to find some filter canisters that fit. It does have a couple of issues that I can work around or ignore. It will fill an aluminum 80, it takes about an hour and the gas engine wants to quit at about 2700psi. If I carefully push on the throttle control lever I can increase the speed of the gas motor to keep it pumping up 3000 psi. The only time this is a problem is when I am filling my own "shop" tanks. My normal working tanks are 2015 twin 38's so the cutting off at 2700 should not be an issue. It take about an hour to fill an 80....after working at dive shops that have big compressors an hour fill time tries my patience. If I am filling tanks while I am doing hydos that should not be a problem. I filled three 80's on less that a gallon of gas, so that is not too bad.

[swimjim]

I converted my MaxAir 35 from gas to 220 single phase. No more worrying about carbon monoxide issues and it's a lot quieter. I used the motor from my "parts" belt floor sanding machine which I believe to be around 4hp. I just had to build motor mounts for it.




Of course, if I need to, I can put the gas motor back on it in about 15 minutes.

[antique diver]

....the gas engine wants to quit at about 2700psi. If I carefully push on the throttle control lever I can increase the speed of the gas motor to keep it pumping up 3000 psi....

I ran into the same problem on Aero Sub, with that engine being underpowered for the additional torque needed to reach full pressure. I put an adjustable sheave or pulley on the engine (available at Grainger), and adjusted it to be smaller than the drive pulley that is now on the engine. Or you could just use a smaller diameter inexpensive pulley. Your compressor will turn a little slower, but will require less horsepower to keep it turning. Or you could use a stronger engine, but the slightly lower compressor speed will also let it run slightly cooler.

The manual for that compressor has a warning to let it warm up well before letting it build pressure. This will help prevent damage to the pistons. You can do that by letting run with the condensate drain valves open until the first stage head is warm. The final stage piston assembly is fairly delicate on this machine, and I have seen a couple of them fail... probably from failure to heed the warning in the manual... which you may not have. Use a good synthetic high pressure compressor oil... not something from an auto supply store.

[captain]

5 horsepower should be enough to run that compressor. Aero Sub shows a 4 horse power motor as normal. It should have an output of about 3 to 3.5 cfm and should fill an 80 in about 20 to 25 minutes. The governor on the motor may need adjusting to get the required speed. Changing the pulley will slow fill time even more.
Also small leaks on a small compressor can dramatically slow fill times and you can't hear them when it is running. I suggest you use soapy water and check for leaks at every connection and at any safety relief valves when it is running.
My compressor is also a 3.5 cfm unit and I expect to see a 100 psi per minute pressure increase when filling a tank. I routinely check that time and if it gets much longer I start looking for leaks.

http://www.olmeva.com/english/aerosub/compact6.html

[antique diver]

The horsepower ratings of engines is questionable, with the Honda used on newer models probably putting out more torque at the desired RPM than the cheap Briggs & Stratton (or copy thereof). There is probably a good reason why they began using a different engine. The Briggs may not be running at its peak torque and or horsepower speed. It's possible that the "5" rating is an exaggeration, or may require a significantly higher rpm... in other words, it may only be putting out 3 hp at its current speed.

The loss of sufficient power on the Briggs model is not an isolated incident on this compressor. If you want to keep the rated rpm and air volume output you may need to go to 5.5 Honda. I chose the lower rpm route because it because a little loss of volume was not a problem since I also had larger compressors. I eventually put a 3 hp 240 volt (3450 rpm) electric motor on that pump so I could use it in my garage.

If you turn the pump faster than its rated speed of 2200 to get more volume, you will also increase the heat production and wear. Not a good idea with that machine. Going a little slower with a smaller drive pulley on the motor has the opposite effect on heat and wear... but you need a little more patience on fill times.

Just a word about rated compressor discharge rates... Many manufacturers exaggerate the real number for competitive reasons!

[antique diver]

....Also small leaks on a small compressor can dramatically slow fill times and you can't hear them when it is running. I suggest you use soapy water and check for leaks at every connection and at any safety relief valves when it is running....

http://www.olmeva.com/english/aerosub/compact6.html

That's a good point, and a fairly common condition. Even a small leak of 1 cfm makes up a large percentage of the rated capacity on the small units. Age and cold weather is particularly bad about making hoses leak around the area where the end connections are crimped on, so be sure to check those areas under full pressure.

[captain]

The 5 HP Briggs on mine runs at 3500 rpm for a compressor speed of 1500 rpm.

[antique diver]

The 5 HP Briggs on mine runs at 3500 rpm for a compressor speed of 1500 rpm.

Captain, The engine speed around 3500 sounds normal, but your 1500 rpm pump speed is lower than the 2200 rpm specs on the link you provided. Do you have the same compressor block? That might explain why yours works. I didn't check the pump rpm on mine, just adjusted the sheave until it didn't bog down the engine. I no longer have it, so I can't check rpm now.

Time2Dive,
If it's taking an hour to fill an 80 you definitely have some air loss, and are delivering less than 1.5 cfm to your 80. I hope you can find an external leak, because the other cause of that could be internal: piston blow-by due to worn rings and/or pistons.

[captain]

I am running an old USD Cyclone made by Luchard. It is rated 3.5 cfm at 1500

[Sandy123]

There was an Aero Sub Plus 6000 dive compressor that came installed on a boat that I purchased. It works but the safety relief valve starts to leak at about 1800 psi and then lets go at about 2000 psi so that is as much as I can fill a tank to. This compressor must be about 25 years old. Does anyone know if you can buy parts anywhere? Or can a safety relief valve be "adjusted" ?

[SurfLung]

- Hey, that's the same filter array as the one I got from Antique Diver for my RIX. You can hand-pack it for economy but you can also buy some great see-thru, pre-packed filters from Lawrence Factor. I have mine set up with the first tube being used as a moisture separator, 2nd and 3rd tube have 13X Sieve, and 4th tube has 13X Sieve, Hopcalite, and Charcoal. VERY nice filter array... Thanks Bill for selling it to me!
- And congrats Time2Dive on your new compressor acquisition and excellent filter array!

[antique diver]

There was an Aero Sub Plus 6000 dive compressor that came installed on a boat that I purchased. It works but the safety relief valve starts to leak at about 1800 psi and then lets go at about 2000 psi so that is as much as I can fill a tank to. This compressor must be about 25 years old. Does anyone know if you can buy parts anywhere? Or can a safety relief valve be "adjusted" ?

Please don't adjust any relief valve unless you know which stage it is on. If it is not the final pressure relief, it is likely relieving an over pressure situation in one of the earlier stages. Some of their compressors (especially gas powered) did have one on the final output that was easily adjustable to set the fill pressure, and if you are lucky that's what it is.

If you would like to post or email me some good clear photos and also indicate which relief is leaking maybe I could advise.