Compressor Newb

[Sub100]

Hi Forum,

I would like to understand how SCBA compressor systems are setup.

I am in a remote area and would like to log some serious hours doing underwater video. So that means figuring out how to set up an air supply.

I would like to buy a Bauer compressor (or one of the other brands out there - not sure who they are but I figure there must be more then 1 manufactuer making SCBA compressors and systems)

I am in a tropical area so it is hot where I am and can be quite humid at certain times of the year.

I am thinking of looking around for a used bauer to start off with, something in the mariner size range (from reading I have done it seems this is a reasonable middle ground between too small and too big)

I am also interested in setting up an air bank so that I can run the compressor at night when its cooler to prolong filter life. My thinking on this is to run the compressor at night because 1/ its cooler and 2/ we generally have grid power most nights. We have a very erratic grid supply and have lots of days with no grid power at all. I could use a gas powered compressor but we have lots of times when there is no gas available either!

So filling an air bank when we do have power and then being able to decant into scuba bottles for diving seems to make sense. I have never used an air bank so not sure of the in's and out's of an air bank. Hoping some of the experienced people here can give me some advice on how to setup an air bank and the do's and dont's of setting up an air bank.

Lots of questions but that will do for now. Thanks for any info.

 

[Sub100]

So filling an air bank when we do have power and then being able to decant into scuba bottles for diving seems to make sense.

OK so more reading through threads here and I have learnt a small thing..... its called transfilling, not decanting. Got to get the lingo right or no one will know what I am on about.

I have 5 x 15 liter bottles that I have been getting filled at 300 bar. The tanks have a threaded screw in fitting on top of the cylinders and the regulators have the same screw thread so that the regs screw into the bottle. I think they were called a DIN fitting ? Not sure how many Cu ft that is per bottle (4500 ltrs of air approx - not sure what that is in cu.ft at this pressure rate).

I am not sure but I think the way transfilling works is that the compressor is connected to a bank of bigger storage cylinders. When the bank is full the compressor is turned off and then one would transfill smaller dive tanks from the bigger bank of storage tanks and the pressure of these larger cylinders in the bank fill the smaller tank connected to it ? I am not sure how a haskel pump fits into all this. Is a boost pump needed for what I am talking about? Is there anywhere on the net that I can read about how this works that anyone knows about?

I have a lot to learn here I know, hence reaching out to you guys.

 

[rsingler]

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A ScubaBoard Staff Message...

To the author of this thread: first, Welcome to ScubaBoard!!
You are asking some great but broad questions, and ones that have been discussed many times on this Board. Some of our members may therefore feel that you are asking others to do your homework for you. Let me gently suggest that you do some searching through this forum, and then refine your questions. Also, with a profile that lists over five hundred dives, for you to say something like "I think they were called a DIN fitting?" will doubtless raise a question as to whether you might be a "troll", or someone who poses questions just to start a controversy. You should certainly know about DIN fittings with that many dives. If this is merely a language issue, I truly apologize.

To the members, let's give this newcomer the benefit of the doubt. Try to keep snarky replies to a minimum. If you see a questionable post, Report it. Thank you.

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[Sub100]

Hi, thank you for the reply.

I stopped diving in 2003 so its been a while. I got certified in 1984 and dived quite alot up till the early 2000's then stopped.

I estimated my dives...cant honestly say how many other then a lot. I never counted them and stopped using a log book in the 80's. In the early 2000's I was diving every other day twice a day for about 6 months of the year ......for about 3 years. How many dives is that? Hence putting around 500 dives...it may be less, it maybe more. I honestly dont know. Also these dives were not with a dive shop or a dive group in the ocean. I was diving by myself with a few locals (I am in Africa) and its in a freshwater lake - so not your usual setup with all the people and gear and the whole scene (did all that with dive shops in Sydney in the 80's). So the diving in the lake was/is all very casual.

I cant remember what the valve fittings were called. As I said the regs screw into the bottle because of the 300 Bar rating of the tanks. They are a very different fittings to the regular A clamp type bottle that is so common. I bought 5 of these bottles in 1999 and shipped them out here and used them heavily up till 2003. They are now sitting in my store room so will get them exported out to get them tested to see if they are still good. For the life of me I cant remember what the fittings were called on these bottles.....other then DIN type fitting. They may have another name, I cant remember. (I bought them 21 years ago and as age sets in the fog increases). I bought 5 sets of Poseidon Regs/BC's and Fins/masks. I am not sure if the regs will still be any good or not...probably need a service and new seals etc. But they were good regs. I've got a feeling the tanks may have been branded Poseidon as well.. cant remember ..it was too long ago.

I have read a lot of posts here in the last few days and did a lot of reading before I posted. I dont know much about compressors or air banks etc and finding it difficult to understand how it all works. I do get its easy if you have been doing it for years but for a newcomer there is much to understand, hence the questions.

To be honest compressors of and by themselves are not that interesting, however given I am in a remote location and want to go back to diving and plan to do a lot of it, I am going to have to learn the ropes of setting up and maintaining a compressor.

I would like to get into Rebreather diving and have read a little about it and see the mention of haskel boosters etc. Its too advanced for me now but it raised the question to me that maybe thats how air banks work - fill up the big cylinders then use a booster to transfill to smaller dive tanks??? I really dont know and there is no one around me or anywhere near to me to ask. I am not by the ocean. My diving is in a freshwater lake.

The thing that brought me here to scuba board was an ad for a video camera housing in the classifieds. I am busy buying underwater camera gear and video gear and as I was looking through the forum I saw this compressor section. Its been something in the back of my mind......getting a compressor. But with all the searching for camera gear and buying that stuff and importing it all (and its fun and exciting to play around with new camera gear) its sort of gone to the back of the list. But now as I focus more on it I realise I am not doing any photo work without sorting out an air supply. Hence posting here. Hope that clears it up. I am by no means a troll. Given my need to setup a compressor and run it for some years so that I can achieve my goals of underwater photography I am glad I found this forum. I see lots of very useful posts and questions and lots of useful replies...just a lot of it is over my head at this time.

My my...look at how long this post got. A sure way to NOT get a reply is to write a wall of text on a forum. But since you thought I may be a troll and not serious I got defensive and felt the need to prove that I am genuine and would like to learn about compressors and how to run a filling station.

Life was simpler when there was no Internet and a troll was a thing that lived under a bridge.

 

[GF99/99]

Hey, glad to see your getting back into diving. I see it says your located in Lusaka so I guess my first question is are able to get a compressor shipped to you easily? second question is what is your budget and how often are you filling tanks? I see you said you have 5 tanks, and yes your correct its a DIN fitting. This is not very many tanks and a basic compressor will easily be able to handle this. I am assuming this is just for fun diving for yourself. My suggestion for you is keep it simple especially since compressors and filling tanks etc. is new to you and you just getting back into diving. Just buy a compressor and your good to go. I think setting up an air bank and getting all the fitting etc in your remote area will be a major head ache. Also no you do not need a booster. Keep it simple and start out basic, get your self the compressor and go from there. Yes latter on if you get into rebreather diving having a booster is nice but save that for latter.

 

[Julius SCHMIDT]

Bank Bottles

 

[Sub100]

Hi Marsh,

Thanks for your reply. It was getting a bit lonely in this thread.

I bought those tanks in Sydney 21 years ago (new) and exported them to Africa in 1999. I am not sure if they would be any good now or not?

I agree with start small and keep it simple and will do that to kick off. But lots of logistical problems here. Its the 3rd world. Where I am on the lake is remote. We have one filling station in town and its often out of fuel. We have grid power but the grid is often down. We do have grid power most nights though and its cooler at night here (20 degrees C or so) so I was thinking it may be better to have some big tanks to fill at night then during the HOT.. (very HOT)day to transfill to smaller tanks as I use them through out the day.

I have bought a new boat and 60HP outboard to dive from, bought the camera and underwater housing etc. Getting set to go....but then because of this forum remembered I have done nothing about figuring out AIR. So here I am.

I have a plot with waterfront to the lake. There is a small island offshore not to far away from me. I plan to blow bubbles in shallow water (10m) to hone my underwater photography skills before I go do the serious stuff in deeper water. I plan to do many many hours of blowing bubbles honing my skills. I will have to look up the dive tables again but I expect to get at least 2 x 1 hour dives per day in 10m of water. Plus my dive buddies who stay out on my perimeter on croc patrol need air too. So that's a lot of gas. Hence wondering if it makes sense to have a "bank" so that I only run a compressor at night to get longer life from filters (everything is imported here so everything hellish expensive) not to mention it being a lot easier/more convenient to "transfill" from a bank rather then start up a compressor every time I need to fill a few bottles.

I used to have 2 or 3 local divers diving with me (croc patrol) so we used to empty all 5 cylinders per day easily. There was a compressor locally back in the day but not now so have to figure it out for myself now.

While diving around the island close to is easy in terms of moving back and forth from home to the dive gorunds is easy its gets logistically difficult as I need to move further afield up the the lake (the lake is 700 Klms long and is very remote - its all in the bush). But I will deal with all that when I get to it.

I can get dive stuff from South Africa. There is a Bauer agent in JHB. So while its 3000 klms away from me to get to a service agent it is doable once a year.

 

[Julius SCHMIDT]

I have 5 x 15 liter bottles that I have been getting filled at 300 bar.

I bought those tanks in Sydney 21 years ago (new) and exported them to Africa in 1999. I am not sure if they would be any good now or not?

Interesting tanks grab some photos of the numbers that will help in finding out, they should be good

 

[Sub100]

Interesting tanks grab some photos of the numbers that will help in finding out, they should be good

I will get some photos when I go back up to the lake. Its raining hard here everyday now so I tend to spend Dec to end of Feb in the capital (Lusaka). However I am going up there in the next few weeks so will get some photos of all the gear.

 

[Sub100]

Hey, glad to see your getting back into diving. I see it says your located in Lusaka so I guess my first question is are able to get a compressor shipped to you easily?

second question is what is your budget and how often are you filling tanks? I see you said you have 5 tanks, and yes your correct its a DIN fitting.

This is not very many tanks and a basic compressor will easily be able to handle this. I am assuming this is just for fun diving for yourself.

Yes I can get a compressor sent in from South Africa. Prefer to buy a used one if I can but will buy new if I have too. It would come up by truck transport to Lusaka and I would take it from there to my place in the bush.

Budget is whatever it takes. For a new compressor I would like to keep it under 30-40K USD for a complete setup including a bank but if it costs more what can I do other then pay? Its not like I have a choice if I want to dive and do my thing.

No not many tanks. I know it all seems like I am rushing but I did do lots of this back in the early 2000's. its just I have been out of it for a long time and now getting back into it. I have always done OC but did do a rebreather dive back in Sydney when a dive shop had a "try a rebreather day" it was a semi close circuit setup. I would dearly love to get into a rebreather but that is some time out yet. Thing is with a rebreather there is no need for lots of tanks. But baby steps...... first have to get the OC up and running.

Reason for all this? I am now retired and want to do a coffee table book on the fish in the lake. Yes it is only a vanity publication thing - it would never pay for itself on a commercial basis. But its what I want to do.

Before any of this happens I need a compressor in my life. I get the distinct feeling acquiring a compressor is going to be the easy part.