Setting Up Perun CO2 Reducer for BESTER Midimagster 1801 MIG/MAG Welding

Hello all

Recently I have become the owner of the "bester 1801" migomat, more precisely the complete set ready to use:
- BESTER Midimagster 1801
- 0.8mm welding wire - 15kg spool
- one-stage cylinder reducer for argon and carbon dioxide with a mini pressure gauge type RBArg / KW-0.25WMm (PERUN MANUFACTURER)
- wire adapter
- welding helmet
- CO2 shielding gas cylinder - 8l capacity
- spare contact tips + gas nozzle
- spray-welding preparation BINZEL 400ml

I assembled the whole set according to the instructions and some problems arose when trying to weld. The welds come out well (as far as I can weld) but the reducer turned out to be the problem. I do not know about migomats, previously I welded with an ordinary electrode welder. I set the output flow from the reducer to 8-12l (differently because I am just learning to choose the parameters). The problem appears when I open the valve in the gas cylinder. Left clock should show tank pressure, right clock should show tank pressure. When I gently open the cylinder, everything is fine, but the output pressure keeps increasing and after exceeding 2.5 bar the safety valve is activated and the gas escapes. The input clock does not show me the pressure in the cylinder because when I open the cylinders more, the safety valve works immediately and the gas escapes. If I gently open the cylinder valve, the clock shows about 3 bars, but after opening the valve harder, the gas immediately escapes and the clock does not show the pressure in the cylinder. As I read from the documentation provided when buying the regulator, the output pressure is a maximum of 2.5 bar, and the input pressure is 1.2-1.4 bar of the output value (i.e. about 3-3.5 bar).
All migomat owners I know open the cylinders at will, one clock shows the input pressure from the cylinder, and the other the set output pressure. Is that the way it should be ?? Such use is very troublesome and a lot of gas is wasted. I am asking for help from more experienced users

The pressure gauge for CO2 is almost useless as the gas is a liquid and is sold by the kilograms, so the cylinder pressure depends on the ambient temperature. In other words, the greater the temperature outside, the greater the pressure in the cylinder (the liquid turns into gas). If it rises to about 190 atmospheres, it blows out the fuse at the cylinder valve. You can give yourself the first pressure gauge only as a guide. You have a well-set flow pressure gauge, i.e. within 8-12 liters, however, the rising pressure is a sign of damage to the reducing valve (damaged as a result of too frequent force-regulation or sudden gas hammer after opening the valve). The only repair method is to replace the damaged reduction valve. I can sell it to you or you can buy it at the welding shop.

thanks for the quick reply
the reducer is new, I use it for maybe 20 minutes continuously. I have never opened the gas cylinder to the maximum, so I think that it did not get damaged due to too much pressure. The safety valve is working, so probably would have prevented it too.
As for the increase in pressure at the outlet, I will describe it in more detail:
when I unscrew the cylinders gently so that the safety valve does not escape anything and adjusts the gas flow on the pressed trigger of the gun to about 8-12 liters, after releasing the trigger (no welding) on the clock, I can see that the outlet pressure is slowly rising. After exceeding 2.5 bar, the safety valve starts working. When I weld, it drops back to the set flow and stays at the set level.

If it is as my colleague describes, then I will have to give it back for warranty and see what they say. But I also don't want to fool around and have it repaired due to my lack of knowledge. So I test it and ask the smarter.
In the future, I will buy myself a mixture of gases, because it is said that it welds better. But that's only when this problem is solved and the gas runs out.
Or maybe it's worth the trouble and find someone who has a mixture and turn the reducer to him to check it?

the reducer is damaged and no matter if you connect it to CO2 or a mixture, the effect will be the same. With reducers, if it works at the beginning, there are no hidden defects in it and I think that the complaint will be unfounded because it was caused by damage by the user. It is normal that when the trigger is pressed, the fuse does not escape because the gas escapes through a different way outside, after releasing it, you cut off its outflow path and the pressure in the reducer body increases to 2.5at and then the safety valve starts letting it through because this is its role. Where did you buy the reducer?

I bought the entire set with the reducer from a store in Włocławek, via the Allegro auction. I decided on the more expensive option, that is the Polish manufacturer "Perun", it seemed to be a better solution. But that's not important, since it doesn't work anyway. By the way, I do not understand how it could break down from excessive pressure, since there is about 200bar in the cylinder and the reducers from what I observed are used to show the pressure in the cylinder and at the outlet to the gun. They should be able to deal with such pressure. Another thing is that I have not unscrewed the cylinder to the maximum.

I read a moment about it and went to check it again. Evidently, according to what the colleague says, the reducer is damaged. The clock shows the pressure in the cylinder about 50bar (I made a full turn of the valve on the cylinder), and the output itself keeps increasing from the set value. There is nothing for me to do but give it back under warranty. It cost me PLN 160, I will not throw it away and buy a new one. Because it works like this from the beginning, so I do not see my fault here. I also started it according to the instructions and in point 5.2 it says that after setting the output pressure, its value should not increase. It dawned on me now. Earlier in the description of the reducer I read that it regulates the output pressure by itself to keep it as we set it. And it seemed to me that this increase in pressure is precisely this regulation. But when it turns out I was wrong, and this is just a flaw.

It doesn't matter if you make one turn or unscrew it all the way, you just have to unscrew slowly at the beginning, if the pressure gauge shows the highest value that is in the cylinder at the moment, you can open it normally. Inside the reducer there is a needle with a thickness of about 1.5 mm and it is damaged by slight bending, which results in an increase in pressure. As I wrote earlier, such a valve can be bought separately, the reducer was bought very cheaply.

Cheap because it is the equipment I bought for hobby work. I do not see the point in buying a reducer for PLN 300-500 (and maybe more expensive, I do not know because I do not know myself) since I will rarely use this migomat. But I also didn't want total cheap for PLN 80.
I will send the reducer under warranty and see what will come of it. I will write when he returns from the warranty.

Thank you very much my colleague "Jacek1983rr" for precise answers

Hello
It took a long time, because if the equipment is not needed, it is hard to find time to send it to the service. I sent the reducer directly to PERUN, previously I called them and received an e-mail about the documents and the form of shipment (I sent them by Polish post, but Perun offers free warranty transport both ways if you use a courier company with which they have an appropriate contract). The warranty has been approved and the reducer has been repaired. It works, the correct adjustment took me a while. The output capacity can be set very precisely, while welding, the output pressure is very stable. During breaks, it increases slightly (e.g. from 10 liters to about 12 liters). In my opinion, it is a very good reducer for an amateur. It works stably and no unnecessary gas is wasted.