Problem with Coltri MCH6

[Wallowa]

No, they replaced the chassis.

Alex and Edward,

What year model is your MCH-6? And where on the frame/chassis did the weld break? Where at the first tower/filter?

Thanks...

Ps...Here is the current PMV valve on MCH-6 Icon @ 1,900psi.... Back Pressure Regulator 6000 psi 1/4" FNPT to 1/4" MNPT

 

[Wallowa]

Alex and Edward,

What year model is your MCH-6? And where on the frame/chassis did the weld break? Where at the first tower/filter?

Thanks...

Ps...Here is the current PMV valve on MCH-6 Icon @ 1,900psi.... Back Pressure Regulator 6000 psi 1/4" FNPT to 1/4" MNPT

A dumb question I know....as I understand it the PMV holds back pressure upstream of the whip and downstream of the filter to assure correct/optimum filtration rate...at 1,900psi...then how does the pressure ever go above that 'downstream' in the bottle being filled....??
Only idea I have is that the PMV 130+bars is a minimum pressure once the compressor comes up to speed and at least 1,900psi is then maintained in compressor while pressure increase in the bottle....sorry just can't visualize it how that PMV accomplishes that....but obviously like my compressor, bottle pressure will climb until it exceeds 232bar PRV setting.

 

[iain/hsm]

4, Oil colour the honey coloured oil seems to go black/grey with a slight metallic look to it, according to the Coltri Technician this is perfectly normal and does not indicate anything amiss, just change the oil at the stipulated intervals,

To describe black oil from a breathing air compressor so soon as "Perfectly normal" is about as normal as allowing a three year old to continue licking out the contents of a Crack pipe he found on the street.
I trust you understand what this black oil is exactly and after consideration to the risks involve are not considering using this type design of pump for breathing air. But enjoy air gun filling. Just saying Iain

 

[Alex Ouroboros]

To describe black oil from a breathing air compressor so soon as "Perfectly normal" is about as normal as allowing a three year old to continue licking out the contents of a Crack pipe he found on the street.
I trust you understand what this black oil is exactly and after consideration to the risks involve are not considering using this type design of pump for breathing air. But enjoy air gun filling. Just saying Iain

I’m only repeating exactly what the Coltri technician told me, bear in mind this guy isn’t employed by a dealer he is factory trained at their Italian facility, his explaination was that the Coltri oil always does this very quickly and it’s no cause for alarm, although he did say he found it as equally alarming as both myself and you now do so, I wouldn’t normally have written bullet points as I have done in my earlier post with specifics but as this is what the Coltri technician told me at their distribution facility in the UK then I see no higher authority, I do test the air and monitor and change air filters as I should, I’m detecting no reason to doubt what I was told given most of my compressed gasses are used in rebreathers I would certainly be aware of it by now.

 

[Mudbags]

I’m only repeating exactly what the Coltri technician told me, bear in mind this guy isn’t employed by a dealer he is factory trained at their Italian facility, his explaination was that the Coltri oil always does this very quickly and it’s no cause for alarm, although he did say he found it as equally alarming as both myself and you now do so, I wouldn’t normally have written bullet points as I have done in my earlier post with specifics but as this is what the Coltri technician told me at their distribution facility in the UK then I see no higher authority, I do test the air and monitor and change air filters as I should, I’m detecting no reason to doubt what I was told given most of my compressed gasses are used in rebreathers I would certainly be aware of it by now.

The mechanical wear that's causing the deterioration of the oil and metal to appear is pretty normal for the MCH-6, so the Coltri dude isn't misleading you by saying they always do that. Unfortunately all compressors are not made equal, MCH-6s are cheap (hence the popularity).

Don't let air quality tests give you false hope. Air can be perfectly clean while a crankshaft bearing is getting ready to explode. Sorry for the doom and gloom, I've seen the damage caused by bearing failure in these machines so I'm just trying to help you get ahead of it.

I'd continue paying close attention to the oil and even changing it out more regularly. It's the best way to spot upcoming failure of internal moving parts. A little metal in the oil after the first few hours is normal but after that you shouldn't really see any. I'm guessing this unit isn't brand new.

 

[Alex Ouroboros]

The mechanical wear that's causing the deterioration of the oil and metal to appear is pretty normal for the MCH-6, so the Coltri dude isn't misleading you by saying they always do that. Unfortunately all compressors are not made equal, MCH-6s are cheap (hence the popularity).

Don't let air quality tests give you false hope. Air can be perfectly clean while a crankshaft bearing is getting ready to explode. Sorry for the doom and gloom, I've seen the damage caused by bearing failure in these machines so I'm just trying to help you get ahead of it.

I'd continue paying close attention to the oil and even changing it out more regularly. It's the best way to spot upcoming failure of internal moving parts. A little metal in the oil after the first few hours is normal but after that you shouldn't really see any. I'm guessing this unit isn't brand new.

Machine was definitely brand new, it’s now got about 50hrs on it, I quite agree on changing oil more frequently than advised, after all to not do so is just false economy, ta

 

[joebob24]

Unfortunately all compressors are not made equal, MCH-6s are cheap (hence the popularity).

A $3000 compressor is considered cheap? I don't think I even want to know how much an expensive one is. My compressor tends to have a little shine in the oil as well, which I know comes from cheap bearings. Sure glad I didn't pay 3k or more for it. I don't think I would be as OK with that.

 

[Mudbags]

A $3000 compressor is considered cheap? I don't think I even want to know how much an expensive one is. My compressor tends to have a little shine in the oil as well, which I know comes from cheap bearings. Sure glad I didn't pay 3k or more for it. I don't think I would be as OK with that.

Very cheap, in fact the cheapest.

... excluding the machines popping up online in China from Happy Fun Time Number One Compressor Company Pty. Ltd. and the like

 

[sbaric]

Hi to all!
Just bought a used coltri mch6 with Petrol engine. It looks ok, does not seem to work to many hours and even the seller claims that it has low working hours.When i went to fill scuba tank for the first time, i noticed that it wont fill over 120 bar. When i close the tank valve or refill valve it raises the pressure ti 220 bar without problem and OPV starts on. Any idea what to check to solve this problem?
Thnx in advance

 

[Alex Ouroboros]

Which OPV is firing? The one directly on the end of the 3rd stage or the one (usually anodised) that is located at the top of the machine near the end of the filling whip?