Servicing a screw RollAir 1500v screwcompressor


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Old 06-16-18, 04:25 AM
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Servicing a screw RollAir 1500v screwcompressor

I have such a compressor mostly for sandblasting in my homeshop - it kind of needs a little care, but it's running in it's EndOfLife periode 48-50.000 hours !

In the first place I re-filled the oil to max-level - and I can live with that for a while.

BUT ...

what magic stuff is inside the oil-separator-filter since it has these horrible prices ?
( here in Denmark the oil-separator-filtert costs as much as I paid for the compressor itself ! )

Any ideas for "a cheap service work-around" ?
 
  #2  
Old 06-16-18, 06:38 PM
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Welcome to the forums.

This is a US based site so many of us have limited knowledge of equipment and repairs in other countries.

If the filters cost that much maybe it's time to replace that dinosaur.
 
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Old 06-16-18, 09:28 PM
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Tricks and experience shouldn't be fenced by borders - what do you think ?

Why buy another one, that makes it even more costly ... I still have to replace the oil-separator-filter in the future and will then still be frustrated over what's inside such a filter.
 
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Old 06-16-18, 09:56 PM
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I doubt there is a cheap work around. That's an expensive compressor and the parts for it are going to be expensive. Most of those filter are designed for operating under high pressure and have paper and metal screen mesh filters inside. The oil droplets are captured inside the filter and then are allowed to drain back into the compressor.

The insides, although proprietary, look pretty much the same.

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Old 06-17-18, 04:33 AM
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I spent about twenty years servicing large screw-type compressors. The air/oil separators ARE expensive, as I recall they ran close to, if not more than $1,000 for the sizes with which I am familiar. Normal life for an air/oil separator was about 8 to 10 thousand hours. For several reasons I do not consider a screw-type compressor suitable for a home shop.
 
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Old 06-17-18, 05:51 AM
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It's robbery by brought daylight with such prices ... the marginal cost of producing them is only a few dollars, I think !

Why do you think a screw compressor is NOT for a home shop ?
 
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Old 06-17-18, 06:27 AM
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LOL and this is simple?

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Source Wikipedia
 
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Old 06-17-18, 06:56 AM
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WHAT can you explain and WHAT can YOU not understand for ME ?
 
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Old 06-17-18, 11:01 AM
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Exclamation This is for home use???

Screw compressors pass a very large amount of oil compared to a piston compressor.
The oil separator, although simple in appearance needs to work properly.
You will loose capacity and see overheating of the screw if the separator is restricted or have a large amount of oil leaving if the media has broken down and been pushed out of the housing.


Really, only a commercial use of a screw compressor would have you put up with the very loud operating noise and cost of a screw compressor
There are no "tricks" that would make a replacement part less expensive.
 
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Old 06-17-18, 11:15 AM
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-->GregH

"... would have you put up with the very loud operating noise and cost of a screw compressor ,,, "

My screw compressor makes NO NOISE compared to a conventional pisten compressor with same capacity !

Are you truing to argu for the very high priced oil-separator-filter, if so, I don't get you !
 
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Old 06-17-18, 06:25 PM
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Are you saying you have 50K hours on the compressor? Did you buy it new or used?
 
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Old 06-17-18, 09:45 PM
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NO, no, I got it very cheap from a company because it had run 48K hours and they thought it was at it's EndOfLife-time, at least I think that's why !

It had been serviced regulary as planned and it is very nice and clean inside.

At my shop it's not placed very optimal - it's in a shed with my garden tools, but I have a cover for it and I cover it EVERY TIME I don't use it - si it's stille very clean outside too.

It has some smaller issues but I live with them.
 
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Old 06-20-18, 11:49 PM
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No one have any comments ... ???
 
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Old 06-21-18, 02:08 AM
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You asked about a work around. None were forthcoming. The parts are expensive, a new compressor would be much cheaper. What else do you want? There's no magic answer...buy the part and fix it or buy a new compressor.
 
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Old 06-21-18, 02:13 AM
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Screw compressors have their place, IN INDUSTRY, where they run 24 hours a day and at least five days a week. They have poor part-load efficiency, the consumables (oil, air filters, oil filters and air/oil separators are all expensive and MUST be changed on a regular basis.

One manufacturer in the US recommends changing the air/oil separator every 8,000 hours of operation OR every year. Doing it on the yearly basis is VERY expensive on a machine that only sees a few hundred hours of operation per year. This same manufacturer also recommends the oil be changed every 2,000 hours if using a (relatively) inexpensive mineral oil or as much as 8,000 hours if using a premium synthetic lubricant OR once a year (either lubricant) regardless of usage. Change air filters and oil filters with every oil change.

That means in home shop service you would change the oil and air filters, the oil and the air/oil separator every single year if following the manufacturer's instructions. This same manufacturer (and I suspect other manufacturers as well but I have no personal experience with them) does NOT sell any internal parts for their compressors. If the bearings or screws wear they sell NEW compressor "heads" for the machine. You simply cannot rebuild these machines in the field.

They also will self-destruct from oil leaks. I had machines rated from about 250 CFM to as high as 3,000 CFM and the rate of oil circulation was hard to believe. The 3,000 CFM machine (800 horsepower) circulated the oil at 200 gallons per minute! It had a capacity of 110 gallons so that meant it took 30 seconds to circulate the entire load of oil. Leaking fittings or, god forbid, a broken oil line meant that the entire charge of oil would be on the floor in less than a minute, no loss of oil pressure shutdown system could stop that machine fast enough to prevent damage from an oil loss.

Finally, the method of controlling the air output on a continuously operating machine by means of a butterfly valve in the intake is extremely inefficient. Start/stop operation has many drawbacks with any compressor but it is especially bad for screws.
 
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Old 06-21-18, 03:52 AM
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Not much DIY help to get here
 
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Old 06-21-18, 04:06 AM
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There is lots of DIY help available. Problem is that YOU don't understand that your "problem" doesn't have a DIY solution.

If you want a screw compressor then you have to "pay the freight" to keep it running. There are no DIY-friendly work arounds for an air/oil separator.

It's that simple.
 
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Old 06-21-18, 04:40 AM
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Ofcause there is a DIY-solution ... but one have to know what's inside such filters before even thinking of any DIY-solution ... and that's was what I asked for in the first place

For sure service-people DON't bother what's inside or if there is a "cheap workAround" - they make a living out of "just replacing it" - and there is a LOT OF MONEY in it !

But I think I'm in the wrong neigborhood here ... so, bye, bye
 
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Old 06-21-18, 05:56 AM
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Well, Bye....................................................................................................................................................
 
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Old 06-21-18, 06:09 AM
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Don't let the door hit your butt on the way out!
 
 

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