Compressor Questions

[paronix]

Hi Guys,

Just wondered if you could answer a couple of questions:

If I'm running the comrpessor outside and I can smell a bonfire or bbq is it best to wait for the air to clear. Anyone been in this situation?

When finished filling, I was told it was a good idea to run the compressor for a couple of minutes at the end. Do you know if this should be done with the filling hose open or closed, so the safety valve blows.

Cheers,
Nick..

[Okeanos]

The filters should remove almost everything, but if your really close to a bonfire or any form of hydrocarbon output it'd be best to wait.

As to running the compressor afterwards, I never have, nor does my LDS. Don't really see the need to as it will stil be generating heat as it compresses the gas. Just open the drains to blow out any trapped moisture then turn it off.

If any of this is wrong I'm sure Windy will be here to correct me soon.

[nigelH]

Originally Posted by paronix

If I'm running the comrpessor outside and I can smell a bonfire or bbq is it best to wait for the air to clear. Anyone been in this situation?

Smell is parts per million or less.
The only time I've heard of things like this being a problem it was a petrol compressor sucking it's own exhaust. A bonfire two gardens up is probably so dilute you'd be pushed to measure it and it's stuff the filters are tuned for anyway. Pour some compressor oil on your hand and remember the cylinders are lubed with this stuff and you stop worrying about anything that goes up the inlet other than Carbon monoxide.

When finished filling, I was told it was a good idea to run the compressor for a couple of minutes at the end. Do you know if this should be done with the filling hose open or closed, so the safety valve blows.

I don't like running a compressor unloaded. It means the last stage is free running while the previous stages are loaded. I've never seen this in a compressor manual. Do the water drains and let it be.

[paronix]

That's great, cheers guys.

[paronix]

What's your take on CO2 build up at the start of running. Do you bleed some gas off for a while at the start before filling?

[nigelH]

Originally Posted by paronix

What's your take on CO2 build up at the start of running. Do you bleed some gas off for a while at the start before filling?

New one on me. Where's it supposed to come from? Oxidised oil?

Our club compressor, as most dive shops, is plumbed straight into a bank. The one at home I don't even start until I've got the cylinders hooked up. There is no way to bleed any off and I'm sure if there was a case for it it would be in the instructions.

[paronix]

Dunno, it was mentioned to me

[Phil Laughton]

Originally Posted by paronix

What's your take on CO2 build up at the start of running. Do you bleed some gas off for a while at the start before filling?

You can't get rid of CO2 from the intake air unless you use a pre-filter (see Bauer systems) but you are allowed upto 500ppm. Under normal conditions you can expect less than 100ppm. Bleeding off your system won't atchive anything as the air coming out of the filter should be at or better than BS EN 12021.

Phil

[the_negligent_snail]

Originally Posted by paronix

Hi Guys,

Just wondered if you could answer a couple of questions:

If I'm running the comrpessor outside and I can smell a bbq is it best to wait for the air to clear. Anyone been in this situation?

Cheers,
Nick..

I would certainly wait until the air clears as sitting on a long deco stop with the taste of BBQ smoke in my mouth would make me bloody hungry!!!

[Pioneer 10]

You won't need to wait any time to let the BBQ smell dissipate as the smoke (smell) is solid particles and will have been removed by your filters! (But its making me hungry just thinking about it!)
You should also let your compressor run for about a minute or so to let the pistons etc heat up and make better seals against the cylinder walls and stop any excess oil collecting in the first filter. The compressor should be run for this time with the valves all open.