Razorcut 45 Internal Air Pressure Regulator set wrong

After struggling with my plasma to get it to cut properly all the while searching for probable causes for the poor cuts, I finally found that the air pressure should be around 75 PSI. After learning this, I noticed the air pressure gauge on my Razorweld Razorcut 45 would not get over 60 PSI regardless of how much I turned up the pressure going into the plasma cutter. I finally called Razorweld and asked their technician if I was doing something wrong or was there a problem with the plasma cutter itself and he told me that it was a problem with the plasma cutter. He told me that this is a known problem with recently purchased Razorcut 45 plasma cutters due to several of the machines being sent out with the internal air pressure regulators being incorrectly set to 60 PSI. He then told me that I should take the cover off of the machine and set the pressure to 75 PSI while air is flowing through nozzle. I assumed the air pressure was correctly set because if you read the owners manual, it states that the air pressure regulator is factory preset to the correct PSI.
I am glad that this is a relatively easy fix but I am somewhat upset that I have been fighting with this cutter and trying to get it to cut correctly when this is a known problem that Langmuir Systems did not make any attempt to notify us about it.
I hope this helps others that are also having problems due to low air pressure.


If you have read this forum, that is the first thing the Razorweld users on here tell new Razorweld owners to do. Open the machine and crank up the regulator all the way and control the pressure with an external regulator.


Hey David, thanks for your reply. I have read several topics on this forum and have been able to solve several other issues but I still have not come across the one that addresses the regulator problem. I’m sure it is there because you say it is but I still haven’t found it even though I have put in several key words associated with this problem into the search criteria. Even if there is a solution buried somewhere within in the hundreds of topics on this forum, when there is a known problem that is affecting every machine sold during a certain time period, it is the sellers obligation to notify every customer that purchased during that time.
By the way, the Razorweld technician did not recommend opening the the internal regulator all the way and using an external regulator to control the pressure.

What you need to do is get a Y or T QD fitting and take the regulator out and mount it on the back of the plasma cutter so you can adjust it as need.

It looks like Razorweld knew it was a problem, although their “several” machines comment is pretty nebulous - could be 5 or 500.

Did they tell you they informed Langmuir so the info could be passed on? Or was it known only by Razorweld who failed to tell anyone unless they called?

Thanks, good idea.

James, after looking up the definition of nebulous, I see you have a point. The number of machines is unclear, vague and hazy. I was just going by what the technician told me. As for the possibility of Langmuir not knowing about the problem, yeah it’s a possibility but not probable. As David pointed out to me, the problem has been addressed in this forum and am sure Langmuir has someone reading this regularly.

I agree they read a lot of posts, but I’ll wager it’s nowhere near the majority. Part of the reason for that is that members generally answer questions or problems well before LS gets a chance!

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Especially since there have only been 10 this year (I constrained my search to this year in the spirit of Razorweld’s “recently” comment). I found 1 from back in March where it was incorrectly set (60psi) and 2 in the last week where it was broken. So not convinced Langmuir could have been expected to know about problems with recent units having it set incorrectly if Razorweld didn’t tell them.

I’ve tagged @langmuirsystems so they will have a head’s up now in case Razorweld wasn’t just blowing smoke and making up an excuse.

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This is not nothing new on the Razorweld regulator, its been going on for many years. This has been talked about on every welding forum there is and some that is no longer on.

I’ll toss my hat into the “check your regulator” group, mine was properly showing 70psi but with torch on it was dropping and holding 50-55 psi which is an abnormally large drop. I swapped in a new regulator and now it drops less than 5 psi with torch on and cuts great.

So be sure you check your pressure when torch is on too


just found this thread.
i have been trying to get mine to cut 1/4" every thing i tried was no help.
didn’t want to cut threw anything thicker than .125"
i just checked my Razerweld gauged and its 68 off and drops to about 62
I do remember reading about it before my XR table got here months ago.
so I am going to open up the internal regulator and install a n additional one on the wall so I can adjust the pressure as I need to.
yes it was frustrating but i knew it was an adjustment that was off. I’ll update after the mods are done

Yep will make a big difference. I turned mine up. Had a small project to cut out of 3/4 it cut nice. But more important don’t buy aftermarket consumables… the one George sell are the best even cut better than the ones langmuir sells


My razorweld 45 is at 70 psi then drops to 59 psi during a cut. My cuts tend to have more dross then I would like. What do you guys have your psi set to for when it’s cutting?

You need to maintain 65 psi for the best cutting , even when the compressor drops to 90 and kicks in. Dropping 5 to 7 psi is normal, 11 psi is a lot you may want to check and find out why.

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what is your pressure leaving your compressor…?
and what is between the compressor and plasma…?

I have a 60 gallon air compressor it’s set to 140 psi at the air compressor it goes threw a water separator, filer/ deccicant dryer and has a after cool installed, I know in the spring I’ll need to install a refrigerated dryer but can get away with it now as it’s -18 and no heat in my shop. I mean even at a full tank when I release the air from the razorweld weld it drops to 59psi and stay at that pressure. I’ll try increasing the psi to 65.