strange questions

[h90]

I have 3 issues with my MCH-6:

1) on my filter was a slightly too small Oring, that means that maybe some air went beside the filter. Is there an simple low tec test for testing the air? I consider just let it out and fill new.

2) My 300 bar MCH-6 overpressure valve is starting to blow at 300 bar. Shouldn't that be approx. 310 bar? Any guide how to adjust it (I didn't look at it carefully, yet).

3) I set the PMV to 140 bar. when the overpressure valve starts blowing the PMV lets the air pass the reverse way. It doesn't do that at lower pressure. So when the tank reaches 300 bar, it blows everything down to 250 bar where the overpressure valve closes again. That's not normal or?

[frogman62]

1) Your description of the O ring issue is not very complete
Where on the filter? inside, outside, on the filter cartridge or ????

2) IF the 300BAR pressure relief is set at 300 then it will relieve at 300. IF you want it to relieve at 145 PSI more -- set it at that pressure. It will still take approximately 3-400 PSI to reset/close after opening.
Do you have the electrical pressure switch set to shut off the compressor at 300 BAR? IF so then you need to reset the Pressure Relief valve at least 150 PSI above the switch pressure.

3) Yes, that is normal . IF you want to stop any reverse flow install a check valve/ one way valve.

In order to help we will need a little more information.
Jim Shelden

[h90]

1) Your description of the O ring issue is not very complete
Where on the filter? inside, outside, on the filter cartridge or ????

2) IF the 300BAR pressure relief is set at 300 then it will relieve at 300. IF you want it to relieve at 145 PSI more -- set it at that pressure. It will still take approximately 3-400 PSI to reset/close after opening.
Do you have the electrical pressure switch set to shut off the compressor at 300 BAR? IF so then you need to reset the Pressure Relief valve at least 150 PSI above the switch pressure.

3) Yes, that is normal . IF you want to stop any reverse flow install a check valve/ one way valve.

In order to help we will need a little more information.
Jim Shelden

1) The filter cartridge is just a tube , open on both sides with the material inside and an Oring outside to seal against the walls. (Strange enough the filter cartridge can be insert both ways, so I insert it that way that the air first passes the white material for water and than the coal, hope that is right). When I insert the filter after refilling it I found out that it can "shake" inside the housing. So I tried an old used filter and it seals with the oring. I than measured the oring and it was approx. 0.2 mm less in cross/section.

2) there is no electrical pressure switch. So I sit there and just when I want to switch the compressor off I get the pressure switch blowing (and half an heart-attack the first time). So I think I should set it to 305 or 310 bar.

3) OK, I just need to close the tank....Just wondered if it is normal.

[frogman62]

h90,
I am surprised that there is not a "in" and "out" for the filter cartridge. Usually there is a seal on the outlet OR the inlet side, not on both, because the filter cartridge is not to designed to hold any pressure - just to control air flow. Usually the filter cartridge has high pressure air on all sides and therefor does not have to stand any pressure differential. The filter chemicals should have some support/spring/foam to keep them from "shaking around"
The flow direction is correct. The white stuff should be a desiccant like Linde 13X or Alumna (inlet direction) and then the activated charcoal(outlet side) and they should be separated with a filter felt. The top and bottom should have filter felt to keep any "dust" from going anywhere also.
You might post a picture so we can see this "filter".
I don't want to be critical but you seem to lack some of the basic technical knowledge of the system. Have you had this compressor for a while or are you new to the compressor?
Jim Shelden

[h90]

h90,
I am surprised that there is not a "in" and "out" for the filter cartridge. Usually there is a seal on the outlet OR the inlet side, not on both, because the filter cartridge is not to designed to hold any pressure - just to control air flow. Usually the filter cartridge has high pressure air on all sides and therefor does not have to stand any pressure differential. The filter chemicals should have some support/spring/foam to keep them from "shaking around"
The flow direction is correct. The white stuff should be a desiccant like Linde 13X or Alumna (inlet direction) and then the activated charcoal(outlet side) and they should be separated with a filter felt. The top and bottom should have filter felt to keep any "dust" from going anywhere also.
You might post a picture so we can see this "filter".
I don't want to be critical but you seem to lack some of the basic technical knowledge of the system. Have you had this compressor for a while or are you new to the compressor?
Jim Shelden

I am new on the compressor, I filled just the 3rd tank. Installed the PMV myself, because the MCH-6 doesn't has one in Europe. There is just one Oring on the outlet side of the filter, but you can put the filter in the housing turned arround so the oring is on the inlet side. I tried that already.
Yes, there is a net, a foam pad, than the Molecular Sieve, another foam pad, the active coal, foam pad and a final net. Funny is that it came with original filter installed, but the valve below it was not installed (so an hole to the outside. It came that way from the factory. So I swaped the Original filter when I got it first.

[rcontrera]

1. Yeah ... I have seen that as well on some filter cartridges. Seems like the o-ring MFG that supplies the filter cartridge MFG is somewhat inconsistent. when inserting the cartridge, make sure that the o-ring is closest to the top. If you turn the cartridge over and insert it, the air will bypass the cartridge all together. If you have the old o-ring, just change it on the new cartridge.

2. If the valve is lifting prematurely, you can adjust the setting easy enough. Just dump the pressure, tighten the cap about 1/8-1/4 turn and start it back up to check the setting. It is basically trial and error on the setting.

3. Yes, it is normal. As has already been said, you could put a check valve on the system if you want. But I think it would just be a waste of money.

[h90]

1) Yeah, thanks....I filled to tanks with some air most probably bypassing because of a wrong oring, and I am selling Orings and having for sure a 1000 Orings which would fit....I could kick myself in the a.... if I could....

2) Thanks, didn't know if it is tighten the cap....

3) OK

Thanks everyone! Now I know more....