using r-410 gauges for both 410 & r-22

so a guy in one of my classes (hvac/r tech school) works in the field already. he said that for months he was only able to afford his one set of r-410a gauges that also read r-22. he said he used them for both for months until he got a set for just r-22. i know there is a cross-contamination chance when doing that but what is the REAL amount of oil that can be contaminate to the other refrigerant. for example if you only have r-410 gauges and use them on a r-22 system.....clean the hoses good and then go to a job using r-410 should you be ok?? obviously we all know it is ideal to have more than one set of gauges but for arguments sake say you could only get your hands on one for the time being.......thanks in advance for any insight.

Do a search here Lot's of threads on this subject.It's ok to use one set of gauges for both.

If reasonably good service practices are followed, there won't ever be enough oil in your hoses and manifold for cross contamination to be even a little bit of an issue.

The larger issue is how piss poor the resolution is on the pressure scale on analog gauges, especially with the larger pressure scale for R-410a.

The normal operating pressure range for R22 tends to fall into the first 1/3 of the gauge travel on the combo R-410a/R-22 gauges, which tends to be less accurate than the middle 1/3 of the gauge travel.

I'm not a fan of analogue gauges at all, their place in our industry is past IMO, but using combo R-410a/R-22 gauges on a R-22 system is an especially heinous thought to me. :gah:

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Originally Posted by mark beiser

If reasonably good service practices are followed, there won't ever be enough oil in your hoses and manifold for cross contamination to be even a little bit of an issue.

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That is what I thought also, thanks.

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Originally Posted by mark beiser

The larger issue is how piss poor the resolution is on the pressure scale on analog gauges, especially with the larger pressure scale for R-410a.

The normal operating pressure range for R22 tends to fall into the first 1/3 of the gauge travel on the combo R-410a/R-22 gauges, which tends to be less accurate than the middle 1/3 of the gauge travel.

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Yes, my r-410a/r-22 combo gauges are analog and I could see how having a seperate manifold for r-22 alone would be a help with the accuracy of the numbers.

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Originally Posted by mark beiser

I'm not a fan of analogue gauges at all, their place in our industry is past IMO, but using combo R-410a/R-22 gauges on a R-22 system is an especially heinous thought to me. :gah:

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So you prefer the digital gauges now?

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Originally Posted by adamste81

So you prefer the digital gauges now?

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Yes, I've been using digitals exclusively for close to 6 years now. My old Digi-Cool BTD-1000 is still working fine, but has been retired to backup duty.
I've never felt good about analogue gauges, and tried other failed digital products over the years before I found out about Digi-Cool.
Before that I was using class 1 accuracy brass gauges.

A strong case could be made that I've gone a little overboard with the digital thing though. :D
I've got primary and backup digital sets for use on both R-22 and R-410a systems, even my recovery/burnout set is digital.
My BTD-1000 isn't in the picture.
http://www.markbeiser.com/HVAC/rando.../temptest1.JPG

The only analogue refrigerant gauges I still have on my truck are a couple of compound gauges for taking oil pressure readings, and those are class 1 accuracy brass gauges. been thinking of going digital with those too.

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Originally Posted by mark beiser

Yes, I've been using digitals exclusively for close to 6 years now. My old Digi-Cool BTD-1000 is still working fine, but has been retired to backup duty.
I've never felt good about analogue gauges, and tried other failed digital products over the years before I found out about Digi-Cool.
Before that I was using class 1 accuracy brass gauges.

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Well as you can tell from my o.p. i am still in school so i just got some $70 analogue gauges for now (all i can afford) but those digital sure do look fancy, and worthwhile. Our teacher will not let us use 410a/r22 gauges on both refrigerants in the lab, he requires we use a separate one for each. Luckily the lab has many r22 gauges available to practice with but he makes it seem like using a compound r410/r22 gauge for use on both is utterly rediculous and unsafe/unprofessional........ but from many techs I know/have spoken with they say the same thing many people here do......ideally get a gauge for each but if all you have is the 410/22 compound gauge then you can use that also. I think the teacher is just trying to teach the "right" way and doesn't want to seem like he is cutting any corners.

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Originally Posted by mark beiser

The only analogue refrigerant gauges I still have on my truck are a couple of compound gauges for taking oil pressure readings, and those are class 1 accuracy brass gauges. been thinking of going digital with those too.

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Mark, is there a reason that you don't use the digitals to take oil pressure readings?

I use my 1200 for it almost daily and it works great.

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Well as you can tell from my o.p. i am still in school so i just got some $70 analogue gauges for now (all i can afford) but those digital sure do look fancy, and worthwhile. Our teacher will not let us use 410a/r22 gauges on both refrigerants in the lab, he requires we use a separate one for each. Luckily the lab has many r22 gauges available to practice with but he makes it seem like using a compound r410/r22 gauge for use on both is utterly rediculous and unsafe/unprofessional........ but from many techs I know/have spoken with they say the same thing many people here do......ideally get a gauge for each but if all you have is the 410/22 compound gauge then you can use that also. I think the teacher is just trying to teach the "right" way and doesn't want to seem like he is cutting any corners.

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Adam,

There is a huge amount of misinformation floating around out there in the world. I commend you for trying to educate yourself.

Think about something, if you will. Spend $70 on gauges now (your number, right?) then spend 70 more in less than a year, and 70 more, and 70 more and 70 more...... You see where I'm going with this. Now, you can drop a few hundred on a good digital set and never have to buy gauges again (at least for the forseeable future) Add to that the fact that your thinking about the refrigeration system will change once you start using digitals, and Mark is right, analog is dead.