Needing help with Hamworthy/american bristol compressor

[wildcat99s]

Hey. I'm new here and have a quick question that i can't find of looking. I was recently given a compressor that i have a couple questions about. Here's what i know about it. The guy who originally bought it did so while on an impulse scuba shopping spree, and after buying all of the other scuba equipment he never really used the compressor, then some time later he passed away and i eventually got it.

It's dated from 1992 and still had the tags and bags over the valves for storage. And the hour meter only had 1 hour on it, so i don't believe it was ever used other than doing the pressure tests and such from the last service, or when it was put together.

And all of this is what is confusing me. Because it should be ready to go, but it's not working as i think it should, tho this is my first high pressure compressor. OK. So the compressor seems to working, and is building up pressure inside of the filter chamber. But for some reason, the check valve isn't opening to allow the air to leave the output fitting.

I've taken the filter chamber apart and it's clean and looks brand new. On the bottom there are 2 caps and the bleed valve. The cap on the left seems to be the over pressure valve and is adjustable, and the other cap is the check valve. and for some reason the check valve won't open. It'll build pressure until the pop valves on the cylinders start popping. Which only takes 6-8 seconds and then i turn it off.

So one time i took out the small pin inside the check valve to allow it to open, which was allowing air to escape thru the hole on the cap, and it was still showing 700psi. so i believe that the compressor itself is working. The spring inside the check valve is very stiff. I tried replacing it with a looser spring and i was able to get a little air from the output, but it was also coming out of the check valve cap hole.

does anyone have any ideas on what could be happening? My fix would be to remove the check valve, and then install a new external check valve. But i'd like to try to fix it before making any mods.

Here are some pics of it along with the serial number plates.

 

[abnfrog]

i cannot believe this to be a 20 cfm ....i sold a bristol that was 18 cfm a few years ago and it was twice the size / hp that this one is .....2 cfm id believe

 

[wildcat99s]

i cannot believe this to be a 20 cfm ....i sold a bristol that was 18 cfm a few years ago and it was twice the size / hp that this one is .....2 cfm id believe

yeah. your probably right. similar compressors i've seen online all have abnormally high cfm on the tags so it's either missing a decimal point, or it's unrestricted flow.

 

[wildcat99s]

So I think I discovered the problem. I removed the check valve and let it pump up and it'll only reach 700 psi. And not the 3000. So maybe a spring weakened in storage. But don't think it's strong enough to open the check valve.

It just may be challenging to find parts for since their so rare

 

[ScubaAl]

Welcome to August Industries - August Industries Inc.

 

[wildcat99s]

So after another hour of messing with it, it's looking like i'm not getting any added compression from the 3rd stage. the popping i'm hearing are from the pressure line valves to keep it from over pressuring before it reaches the 3rd stage. And since the 2nd stage blow off valve is 650 psi. That's what i'm pressure reading. So it's looking like the compressor isn't building enough pressure to open the check valve. Which answers my original question.

So does anyone have any idea on where i could pick up a working 3rd stage? From what i've read, the 3rd stage is a unit an can't just be rebuilt. But that's my job for today. Research it and decide what i want to do or try to find one.

 

[wildcat99s]

so an update after a couple days of tinkering with it. The 3rd stage isn't working and can't figure out why. I did a compression test and i'm getting 650psi before it enters the 3rd stage, and the pressure rises very quickly when i did that test. but with the 3rd stage connected, it's forcing the air thru the 3rd stage and slowly rises back to 650psi but has no added compression.

but i did find out that the filter i have has a check valve that will only open up once the pressure rises to above 2000psi. so that answers my original question.

 

[wildcat99s]

So a final update to anyone who was interested. I was able to get the compressor up and working. and it's working great, tho i need to get a new whip and attachments before i fill a bottle, and i'm gonna do a air purity test to double check the quality before i breathe it for an extended period of time.. But this compressor puts out some major air, and while i haven't checked it yet. i can see it doing an easy 20cfm unrestricted flow.

The root of the problem was the 3rd stage piston was seized from a little surface rust from the 28 years in storage, and it had some imperfections on the inlet valve, exhaust valve seat, and valve plate that had to be cleaned up and flattened a little. It probably would have been alright since it was only off by .00007" and was probably within the original tolerances, but i got it down to .00002" on flatness. Overall it took me longer to fix than it should have because i had some miscommunication with expert over the phone, as i didn't know the official names of each part so it took me a little while to understand exactly what he was trying to ask and tell me.

But i did a test fill of the filter canister and it reached 4000 psi before i turned it off. so i'm super happy. But the good news is i know this compressor basically inside and out shouldn't have any more problems working on it in the future.

But if someone needs any help on these old hamworthy compressors. Look up Jim Shelden sporting goods in Kansas and he knows them inside and out. and he does sell parts, accessories and other compressors. I found his name somewhere in this forum and wanted to give him some credit for putting up with my constant questions.

 

[Chris H]

But if someone needs any help on these old hamworthy compressors. Look up Jim Shelden sporting goods in Kansas and he knows them inside and out. and he does sell parts, accessories and other compressors. I found his name somewhere in this forum and wanted to give him some credit for putting up with my constant questions.

Jim is a wealth of knowledge, for sure. He has always been helpful with questions I've had about my Kidde.

 

[sergio55]

hello how are you dear, I contact you to consult you, looking for something about my compressor, I found that you have the same one that I have, and now I would have to do maintenance and I do not have any information about it, could you tell me what do you know about him? for example, what type of oil does it take and how often should I do maintenance work since I have never done it before, I would also appreciate it if you could provide me with all kinds of information about it, I could tell you that I recently acquired it and tried it by loading my fiber scuna of 6.8 liters at 300 bar and I loaded it without problems, now it does not even reach 200 bar, could you guide me what could be happening? Without further ado I say goodbye very carefully, sorry if I bother you, best regards.