ATLAS COPCO COMP

[Rickt]

I have a very old Atlas Copco compressor [1969 model] bought second hand nearly 30 years ago , still going strong .When I bought it I serviced it ,took it to bits ,painted it and re-assembled it and have used it on a number of jobs . I've noticed over the years there has been a bit of oil leak-edge and I want to service it again . But , I have no information about it and there's nothing on the internet .Can anyone tell me what sort of oil I put in . I cannot remember what I used back then ,whether it was engine oil , gear oil or what . Many thanks .
Here's a picture I of a similar model except mines not 3 phase .

 

[Rig Pig]

At a guess hydraulic oil, ATF or recip. Compressor oil - machine mart sell 1ltr bottles.

 

[normspanners]

iso vg 100/ sae 30 is pretty standard oil for piston poppers
in cold weather you might want to go a little thinner.

 

[TurtleDude]

http://uk.rs-online.com/web/p/produ...&istBid=tztx&gclid=CLvtj9n0yMYCFSbItAodjpcF4A

This should do the trick.

 

[Rickt]

Thanks chaps . Not knowing anything about them at the time and still not knowing "nowt" now I may have put engine oil in it .It's still working and still a good-un .
I'll look after her better now .cheers .

 

[TurtleDude]

Thanks chaps . Not knowing anything about them at the time and still not knowing "nowt" now I may have put engine oil in it .It's still working and still a good-un .
I'll look after her better now .cheers .

The danger is with motor oil designed for a car engine is that it may start foaming. This reduces its lubrication properties and usually ends in disaster.

Your old piston machine is probably so worn it makes little or no difference (or air!).

You'd be surprised how much older tech compressors cost to run compared to modern efficient ones. This mainly applies to rotary screw compressors, as recips run very low duty cycles (or should).

 

[Rig Pig]

The danger is with motor oil designed for a car engine is that it may start foaming. This reduces its lubrication properties and usually ends in disaster.

Your old piston machine is probably so worn it makes little or no difference (or air!).

You'd be surprised how much older tech compressors cost to run compared to modern efficient ones. This mainly applies to rotary screw compressors, as recips run very low duty cycles (or should).

Most of the proper recips are 100% duty! Only the toy ones have limits.

 

[TurtleDude]

Most of the proper recips are 100% duty! Only the toy ones have limits.

Really? Are you sure about that?

Most recips have a duty cycle of around 50%. The best ones only offer a duty cycle of 60-70%.

Feel free to correct me, as obviously I know nothing.

 

[Rig Pig]

Well, the main compressors at work have been on continuous duty since the mid 60s. .....

If your looking at Machine Mart etc toy compressors then yes the duty cycles will be limited, however the better machines are capable of continuous running.

 

[normspanners]

Some piston compressors run all day but maybe dont compress all day they just unload and stop pumping pressure when a set pressure is reached.
To help explain ;

Oil-lubricated piston compressors are by far the most common in the 5-30 hp range. unless you have medical air application and a few other special applications, then oil-lubricated is most likely better for you.

There are splash-lubricated compressors and pressure-lubricated compressors.

A splash lubricated compressor uses a dipper on the end of the connecting rod. When the crankshaft turns, usually between 400 and 1000 rpm, the dipper splashes into the oil, causing the oil to distribute throughout the lower end of the pump. Most of the ones you'll see are splash-lubricated. It's a very simple and effective method of lubricating the pump. It's also inexpensive to manufacture so it keeps the initial cost of the compressor down. In nearly all cases, splash-lubricated recip should only have a duty-cycle of about 60%.
A pressure lubricated compressor uses an internal oil pump to force the oil up the connecting rod to make sure key parts of the pump are lubricated. The pump will require a certain oil pressure in order to run. You'll see an oil pressure gauge on the pump to indicate the oil pressure. Some have an oil-filter on it and some do not. However, if you see an oil filter or a gauge on the pump crankcase, then you're looking at an pressure-lube pump. A pressure-lubricated pump may also used a dipper to splash oil around, as well. Pressure lubricated pumps can sometimes be rated with a 100% duty cycle. Pressure-lubricated pumps on average will last longer and have a higher duty-cycle than splash-lubricated pumps. However, they usually cost a lot more. You get what you pay for, so you'll have to balance initial cost versus reliability and duty-cycle.

Duty-Cycle

Duty-cycle is one of the most important considerations when buying a compressor for your business, but it's one of the most overlooked. If the compressor is for your house or if your business barely uses the compressor, duty-cycle is not much of a factor. However, if you run the compressor a lot, and the compressor is essential to your business, then duty-factor is extremely important.

A compressor's duty-cycle is the percentage of time, while it's in use, that the compressor can be running full-out. The other percentage or time it needs to be off or running unloaded. If you have a splash-lube pump, you should have about a 60% duty cycle. That means over a 10 hour work day, the compressor should run about 6 hours and be off about 4 hours. Of course, the compressor will not run 6 hours straight and be off four hours straight. The compressor will turn on and off, depending on the air demand. It should average about 60% of the time running.

So now let's look at duty-cycle when it comes to sizing a compressor. If you plan on getting a compressor for your business, you'll be using it all day, and you need 15 CFM pretty much all day. If you're looking at a splash-lube piston compressor, you need to take that 15 CFM and divide by 40%. That gives you 25 CFM. Your typical 5hp piston is about 18 CFM.

If you bought the 18CFM splash-lube piston based on the fact you needed 15 CFM all day, you'd break the pump in about 6 months, maybe a year. You need the 7.5 hp piston which is about 25 CFM. Alternatively you can get a 5hp rotary screw that's 20 CFM. A rotary screw has a 100% duty-cycle, but it will cost several times more initially. You could also get a pressure-lube 5hp piston, which could most likely handle the high duty cycle.

If you just need a quick burst of 15 CFM that last an hour or less, then you'd be fine getting the splash-lube based on that CFM. However, if you needed a sustained flow for several hours, you need to account for the duty-cycle of the pump.

This is a common mistake that many companies make. Your compressor company should be trained to recognize that situation, so that's why for your business you should get assistance from a compressor company with professionally trained sales personnel. Home Depot has "home" in the title, and the compressors there are built for that market. You'll often see in the fine print that the warranty is reduced to only 3 months if you take a home compressor and use it for your business. The reason is duty cycle.

There's nothing wrong getting a compressor from a big-box store if you're using it at your house - you probably don't need an industrial compressor for your garage.

A "home depot" compressor will probably work just fine for your home. For your business, however, you should come to the professionals and let them size the compressor correctly for you.

 

[TurtleDude]

Some piston compressors run all day but maybe dont compress all day they just unload and stop pumping pressure when a set pressure is reached.
To help explain ;

Oil-lubricated piston compressors are by far the most common in the 5-30 hp range. unless you have medical air application and a few other special applications, then oil-lubricated is most likely better for you.

There are splash-lubricated compressors and pressure-lubricated compressors.

A splash lubricated compressor uses a dipper on the end of the connecting rod. When the crankshaft turns, usually between 400 and 1000 rpm, the dipper splashes into the oil, causing the oil to distribute throughout the lower end of the pump. Most of the ones you'll see are splash-lubricated. It's a very simple and effective method of lubricating the pump. It's also inexpensive to manufacture so it keeps the initial cost of the compressor down. In nearly all cases, splash-lubricated recip should only have a duty-cycle of about 60%.
A pressure lubricated compressor uses an internal oil pump to force the oil up the connecting rod to make sure key parts of the pump are lubricated. The pump will require a certain oil pressure in order to run. You'll see an oil pressure gauge on the pump to indicate the oil pressure. Some have an oil-filter on it and some do not. However, if you see an oil filter or a gauge on the pump crankcase, then you're looking at an pressure-lube pump. A pressure-lubricated pump may also used a dipper to splash oil around, as well. Pressure lubricated pumps can sometimes be rated with a 100% duty cycle. Pressure-lubricated pumps on average will last longer and have a higher duty-cycle than splash-lubricated pumps. However, they usually cost a lot more. You get what you pay for, so you'll have to balance initial cost versus reliability and duty-cycle.

Duty-Cycle

Duty-cycle is one of the most important considerations when buying a compressor for your business, but it's one of the most overlooked. If the compressor is for your house or if your business barely uses the compressor, duty-cycle is not much of a factor. However, if you run the compressor a lot, and the compressor is essential to your business, then duty-factor is extremely important.

A compressor's duty-cycle is the percentage of time, while it's in use, that the compressor can be running full-out. The other percentage or time it needs to be off or running unloaded. If you have a splash-lube pump, you should have about a 60% duty cycle. That means over a 10 hour work day, the compressor should run about 6 hours and be off about 4 hours. Of course, the compressor will not run 6 hours straight and be off four hours straight. The compressor will turn on and off, depending on the air demand. It should average about 60% of the time running.

So now let's look at duty-cycle when it comes to sizing a compressor. If you plan on getting a compressor for your business, you'll be using it all day, and you need 15 CFM pretty much all day. If you're looking at a splash-lube piston compressor, you need to take that 15 CFM and divide by 40%. That gives you 25 CFM. Your typical 5hp piston is about 18 CFM.

If you bought the 18CFM splash-lube piston based on the fact you needed 15 CFM all day, you'd break the pump in about 6 months, maybe a year. You need the 7.5 hp piston which is about 25 CFM. Alternatively you can get a 5hp rotary screw that's 20 CFM. A rotary screw has a 100% duty-cycle, but it will cost several times more initially. You could also get a pressure-lube 5hp piston, which could most likely handle the high duty cycle.

If you just need a quick burst of 15 CFM that last an hour or less, then you'd be fine getting the splash-lube based on that CFM. However, if you needed a sustained flow for several hours, you need to account for the duty-cycle of the pump.

This is a common mistake that many companies make. Your compressor company should be trained to recognize that situation, so that's why for your business you should get assistance from a compressor company with professionally trained sales personnel. Home Depot has "home" in the title, and the compressors there are built for that market. You'll often see in the fine print that the warranty is reduced to only 3 months if you take a home compressor and use it for your business. The reason is duty cycle.

There's nothing wrong getting a compressor from a big-box store if you're using it at your house - you probably don't need an industrial compressor for your garage.

A "home depot" compressor will probably work just fine for your home. For your business, however, you should come to the professionals and let them size the compressor correctly for you.

This.

 

[TurtleDude]

Well, the main compressors at work have been on continuous duty since the mid 60s. .....

If your looking at Machine Mart etc toy compressors then yes the duty cycles will be limited, however the better machines are capable of continuous running.

Please read Normspanner's reply below, since you're sadly mistaken.

Nobody here is comparing Machine Mart chinese specials to Bellis & Morcom VH28N's.

Maybe your compressors at work are Rotary Screws?

 

[Rig Pig]

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[Rig Pig]

Ingersoll Rand and Junair also manage to provide 100% rated recips.

Our gas export compressors are also Reciprocating and run at full capacity continually.

 

[brightspark]

well my compressor works 24 seven or it did do when it was fitted to the engine on a wagon for the airbrakes

 

[TurtleDude]

well my compressor works 24 seven or it did do when it was fitted to the engine on a wagon for the airbrakes

..so you were operating the the brakes 24/7? Bet you didn't go very far...

 

[TurtleDude]

Ingersoll Rand and Junair also manage to provide 100% rated recips.

Our gas export compressors are also Reciprocating and run at full capacity continually.

Do they really, are are they running, and cycling as described in the previous post?

If they're running at 'full capacity' as you claim, then someone sized them wrong. Fact.

Good luck with your Quincy, Junair and IR recips running flat out 24/7/365. The world has moved on for these sort of applications and now use rotary screws.

 

[the artfull-codger]

The brakes might not be on 24/7 but the compressor would be turning 24/7, I have a similar set up to bs but mine's a clayton dewandre pump from a waggon, so they have to be reliable pumps for the work they do,I built it 44 yrs ago, & still going strong.

 

[TurtleDude]

It wouldn't be making pressure 24/7 unless you had some serious leaks.

On load/off load, different kettle of fish my old son.

 

[the artfull-codger]

It wouldn't be making pressure 24/7 unless you had some serious leaks.

On load/off load, different kettle of fish my old son.

If you read my post I said it was turning 24/7 I didn't say it was pumping 24/7 indicating it's a reliable well made pump, unlike a lot of the fast running noisy compressors from the far east today "my old son"