New compressor?

[PekkaNF]

Old oiles italian compressor is wearing out. It has lasted over 22 years, pretty good. Now it pumps max. 3 bars and smells funny.

Now I would like to have:
* Reasonable quality, but not overy expensive.
* Floor space is important, vertical form factor is desirable
* No need to transport, but might need to move outside or around the house ocassionally, sort of semi permanent installation.
* Lowish noise level good
* Max capacity, least 2,2-3 kW, I have three phase, but three phase models seem to expensive

This would cost around 700€


CPRA 50 MV30 VS Piston compressor, I have been told that compressor is machined and manufactured in Italy. Direct drive, but low rpm.
http://tuotteet.etra.fi/en/g23869624/


This would cost around 400€, but is made in china and light weight for 90 litre tank. But compressor is belt driven. Pretty high dB value.



https://www.ikh.fi/en/compressor-230v-2-2kw-330l-90l-vertical-xt90330

These are probably painted with different names on them.

Any suggestions, recommendations or advice?

[awemawson]

Why not refurbish the one that you have? Hone the bore, new rings and pistons, sort the valves (possibly just flap valves rather than car type)
Then send me the 700 euros !

[ddmckee54]

Be careful of the specifications for new compressors, sometimes it seems like there is a lot more Marketing in the specs than there is Engineering - if you know what I mean.

I recently saw a YouTube by AvE about compressor ratings and it pretty much agreed with my own experience with compressors.  Only my experience was with a MUCH larger compressor - 900HP and 4000cfm@100psi.  Still amounted to the same BS, just bigger numbers.

Don 

[mattinker]

Pekka,

take it appart, see what could be done and then decide!

Regards, Matthew

[PekkaNF]

Why not refurbish the one that you have? Hone the bore, new rings and pistons, sort the valves (possibly just flap valves rather than car type)
Then send me the 700 euros !

Pekka,

take it appart, see what could be done and then decide!

Regards, Matthew

Both suggestions (maybe excluding the sending the money part...) would be normally high on my list - and it is.

This old italian job is "oiless", it is about 1,5 kW and 20 litre tank, great for moving around, but not that great on capacity. Since it is oiless, it is not that great for refurbishment (I checked the compressor innards 10 years ago and clean up caked parts and relubricated the piston thinggy. Compressor is shot, pressure switch/valve leaks (and there is not cure but to replace it), relieve valve leaks, and original manifold/pressure regulator/couplings are shot. I would be looking some serious money to refurbish it and still would have low capacity. I am going to repurpose it though.

I need to check the tank and if that is good, I am going to mount one or two Jun-Air silent compressors to it to provide low small amount low noise compressed air, most of the time I need only a little air and assurance that I don't need to wear my brown pants when compressor kicks in. Because the tank is small, maybe I can mount it on a upper corner of the garage, where it will not take up floor space.

This new one would serve occassional and media blasting, spray painting, big nail guns and such. I prefer something that will last.

Be careful of the specifications for new compressors, sometimes it seems like there is a lot more Marketing in the specs than there is Engineering - if you know what I mean.

I recently saw a YouTube by AvE about compressor ratings and it pretty much agreed with my own experience with compressors.  Only my experience was with a MUCH larger compressor - 900HP and 4000cfm@100psi.  Still amounted to the same BS, just bigger numbers.

Don

I am aware that the numbers used to market compressors (intake air volume with no back pressure) is indicative, but not more than that. Greater insult is that compressors are sold with "free air capacity" (USA CFM) and tools are sold most often with compressed air volume

I would greatly prefer if the compressor marketeers would candidly tell the output air volume at 6/8/10 bars of tank pressure and a graph that show PV-relationship AND also the compressor duty cycle (mostly at best 50% with 10 mins on, 10 mins off with these piston compressors).

I am aware of this, I can do with this size compressor, just need to limit use and size of the tools. Impact driver is no problem, works fine with my old compressor, old compressor struggled with my paint guns, only touch up paint gun was near 100% usefull whle compressor was running less than 50% duty cycle.

Now back to OP, Does anybody has these or has experience on similar or close cousins of these new vertical compressors that are not exactly cheap, but are not near Kaiser or Atlas-Copco price?

One thing I am worried is that neither seem to have good arrangement for tank condensate removal.

My gut feeling is to gravitate towards CP "italian" compressor, it has 50 litre tank and weights the same than "chinese" compressor with 90 litre tank. That should indicate as much as manufacturing plant location.

[PekkaNF]

Right.

Ordered Chicago Pneumatics CPRA 50 MV30 VS


    Product code 10380019895
    Product name Piston compressor CPRA 50 MV50 VS
    Technical name CP 1121360252

Technical data:

    Cylinders 2
    Power kW 2,2
    Rotational speed (rpm) 1 450
 
- 330 l/m
- Technology: Piston 10 bar
- Noise level: Standard
- Vessel size: 50 l
- Weight: 60 kg
- 800 X 380 X 680 mm

Small and hopefully not too noisy.

Maybe I'll start stripping off the old italian small compressor and fitting a small "silent" compressors

[chipenter]

I had a large propane tank tee in to my compressor gave me a lot more reserve , I intend to run lots of pipes in my shed as a reservoir , it's surprising how much air is in pipes .

[awemawson]

My air is distributed between several building underground using 25 mm blue MDPE water pipe, and also round the inside of those five buildings as a main with drops to the service points. There is far more storage in the pipework than in the tank !

[PekkaNF]

Thank you, the compressed air pipe work is something I don't have any design or installation experience. I only have used some. Old times they used to be metal and listed down to far end to collect condensate into a watter trap at the the end of the line. branching to use point was T at the top of the trunk line and swan neck pipe down - not to draw condensate I believe. And that is all I know.

I am considering first only one side of the garage. I don't know which pipe system to use, but plastic pipe sounds good.

I have anecdotally read about using the water pipe hardware. I am sure Andrew has done homework, therefore I this is something I need to have a look firs. I think there was a thread somewhere, when screw compressor arrived or something. Search will reveal.

However, this plastic pipe choice. That pipe looks and sounds similar that is used here. I only need probably less than 10 metres of trunk and some maybe 4-5 outlets.

I googled with exact words and firs hit was this:
https://www.plasticdrainage.co.uk/mdpe-water-supply

"It should not be used for the conveyance of gases, oil, petrol, diesel or compressed air. The system is suitable for use with cold water (maximum temperature 20C) with a working pressure of up to 12.5 bar."

Probably denial for compressed air use is due to fear of higher operating temperature and oil fog in the compressed air? Maybe the fittings might be compromised or simply it is not considered as intended use for numerous of legal, commercial or aproval grounds.

How much this is a factor in real use?

I am getting a little wary with plastics incompability, latest observation are the fluerecent roof lights installed 10 years ago...the transparent covers are becoming too brittle to handle. And yes, there has been UV, very small and ocassional use of glues and resins that might emit solvents and least one can of paint has pretty much all solvents leaked out.

Pekka

[awemawson]

Do not use plastic drain pipe. It's usually a hard plastic and relatively thin wall.

The pipe that I'm using is 25 mm MDPE usually used as the incoming water service pipe in houses in the UK. It is service rated at 10 BAR or about 150 psi . I distribute at 100 psi and all my  air goes through a desiccant silica gel drier of my own construction (described on this forum) which has completely eliminated moisture problems.

I have been using MDPE water pipe for over twenty years and have had no problems with deterioration..I have in all that time only had one problem. I had a Tee joint one branch of which wasn't used and was blanked with a blanking plug in a slightly harder plastic. It blew off once when I was experimenting increasing the compressor pressure and I concluded that the retaining gripper hadn't bitten into the plug enough as it was harder than pipe, and that I hadn't tightened it fully. The same joint and blanking plug have now been in service after refitting for several years with no problem.

[chipenter]

Push fit water pipe will withstand 1500 psi , Toolstation sells black water pipe as air pipe and fittings but they are the same as domestic 22 or 25mm pipe holds a lot of air .

[PekkaNF]

I thought that the pipe I linked is the one?

Build Plumb Plastics supply MDPE water pipe (Alkathene) in diameters including 20mm, 25mm, 32mm, 40mm, 50mm and 63mm, in coil lengths of 25m, 50m, 100m and 150mtrs. Our pipe and fittings are WRAS approved and conform to BS EN 12201.

We stock MDPE in both blue and black. Blue is for potable (drinking) water and black (pumping main) is primarilly for non-potable water i.e. seawater, pumped foul & grey water etc. 

https://www.plasticdrainage.co.uk/mdpe-water-supply

Anyway, that was usefull information. But just to confirm: Are we talking about same product?

[Muzzerboy]

There are compressed air versions of the push fit systems we see as plumbing systems, made by the likes of John Guest etc. Toolstation stock some of them. Look in "compressed air tools" https://www.toolstation.com/power-tools/air-tools-compressors/air-tools/c256

Not much point using plumbing components when pukka compressed air components are available? They don't look a lot more expensive. I expect other stockists keep a broader range of parts.

There's potentially(sorry!) a LOT of energy stored in compressed air, so you may need more than just brown / rubber underwear if one of those fittings came loose....

[awemawson]

Push fit water pipe will withstand 1500 psi


No way would I run 25 mm water pipe at 1500 psi as quoted above. 150 yes no problem

This is the stuff I use (I keep a stash of spare!)

[Pete W.]

Andrew,

You really ought to keep caps on the ends of your stash of pipe - you don't want to give any sheltering spiders the bends when you cut off a length to put into service!! 

[awemawson]

There are never enough caps - a 50 metre roll comes with two caps, and of course you end up with far more lengths than you started with, all be it totalling the same length !