R410A Flared couplings

zmann96

I'm getting ready to install a mini split system 30K heat pump compressor with 4 zones. I going with flared connections. I don't want to braze due to locations and potential fire hazard. I was looking at the brass flared couplings on Supply house but there isn't any specs on them. Does anyone know if they are OK for 410 with 500-600 psi ?

SuperTech

I can't answer your question but personally I would just solder with Stay Brite #8. I don't trust the factory flares that come on line sets, I would feel the same way about those couplings.

ChrisJ

SuperTech said:

I can't answer your question but personally I would just solder with Stay Brite #8. I don't trust the factory flares that come on line sets, I would feel the same way about those couplings.

You wouldn't trust brass male flare couplers?

They're no different than what's on the mini split it self.

zmann96

not sure I would trust silver solder, 410 can get up to 500 - 600 psi. thanks for your response.

ChrisJ

zmann96 said:

not sure I would trust silver solder, 410 can get up to 500 - 600 psi. thanks for your response.

I've always heard rumor that vibration is the reason for brazing vs softsolder.  Allegedly even plumbing solder will handle 500+ psi just fine.

I've also heard claims that flux is another reason.

pedmec

Silver solder is rated for 10,000 psi.

Mini-splits come with line sets for their units. If they are too long you cut the ends off and re-flare. You don't want to put a flared coupling in the middle of a lineset unless you absolutely have too. Potential leak point and most installers would not assume the there is a joint in the middle when they are looking for a leak.

JUGHNE

All minisplits I have installed or seen have flare connections on the service valves at the unit.

Does anyone actually braze/solder at the unit valves?

ratio

Silver solder joints in the middle of the line set if your have to, better to buy a longer line set if you can. Don't use the flare nuts that come on the line set, use the ones that come with the mini splits. Especially don't use the factory flare on the line sets, it's just there to keep the nut on, even if you use the line set nut you'll need to reflare it.

ChrisJ

I like to use nylog when making the flare.   Thoughts?

ratio

I do too. It's basically just sticky oil.

mattmia2

Is it oil or is it super glue like loctite?

pecmsg

Just thickened oil. 

EBEBRATT-Ed

I don't know what is in Nylog and don't really care. I think of it as never seize for refrigeration fittings. It is also allowed to be used because if a little gets in the system it apparently causes no harm. Not that you want to be dumping gobs of it in the system

As far as soldering, brazing and flaring goes.. brazing or sliver soldering is #1, soft soldering like staybrite #8 is #2 followed by flaring. They are all good in their place if done correctly. Then there is the crimp stuff

Harris says a stay brite joint is stronger than a brazed joint because it doesn't anneal the tubing and they have the tests to prove it.

But I have herd the real reson for brazing is if the building is on fore the brazed joints won't fail as fast causing phosgene gas.

pecmsg

A brazed joint is actually weaker then the original copper due to the heat / cool cycle. 

SuperTech

ChrisJ said:

SuperTech said:

I can't answer your question but personally I would just solder with Stay Brite #8. I don't trust the factory flares that come on line sets, I would feel the same way about those couplings.

You wouldn't trust brass male flare couplers?

They're no different than what's on the mini split it self.

I was thinking of the flare couplings with female ends on both sides.

archibald tuttle

what about this. i was coming to start a separate thread, but this looks like just the place.

Insofar as I'm vaguely aware, nylog is a joint lubricant and very modest sealant based on refrigerant oil (you predominately get better performance because the lubrication allows more pressure to be applied to the joint although the material and also provide a little bit of tacky resistance at the truly microlevel, i.e. all but invisible, scratch. so you use the blue for POE systems like 410A (although it is marketed as universal) and red for R22 and other mineral oil lubed systems. (I profess ambivialence as to any benefit to keeping the red around since the blue is supposed to be universal . . . ).

now comes expensive but sexy looking "flareseal" which is either so new or so useless that it has made very little market penetration. from what i can tell this is the little cone shaped washer that sometimes comes with larger flares and is supposed to seal better by counter intuitively adding more sealing surfaces although I suspect on the principle that it helps take up possible idiosyncracies in alighnment or fit between the tube and fitting surface. In this approach the cone washed is then coated with a stiffer more gellike nylog competitors' surface lubricant/sealant. i would still want nylog on the threads so they ain't going out of business. but this looks interesting. when i first saw it, i thought it was actually some kind of really robust silicone rubber seal, which only makes me wonder at that as a possibility although the rotating pressures of a flare maybe do not favor such a material in assembly.

but what the heck are the seals made out of in the press style refrigeration fittings? I'll admit, i haven't gone that way yet, but i don't know why since they have 'em to fit my milwaukee tool. And I was on a job the other day where multiple linesets were joined on the run with press fittings that will be inaccessible after finish, so i guess whoever installed them believes in their longevity.

brian

archibald tuttle

pedmec said:

Silver solder is rated for 10,000 psi.

Mini-splits come with line sets for their units. If they are too long you cut the ends off and re-flare. You don't want to put a flared coupling in the middle of a lineset unless you absolutely have too. Potential leak point and most installers would not assume the there is a joint in the middle when they are looking for a leak.

think this is 100% so, but it begs the question: if you don't want a flare on the run because it is a potential leak point, why do you want a flare at the end? I believe the epa manual says that the average life of refrigerant charge is 7 years IIRC. i have to believe that flares are 90% or even 99% of the problem with 410 minisplits. i've got 50 year old refrigerators working fine on their initial charge. Now refrigerators, thankfully, don't use 410 but, more importantly no field terminations so they can even use flammable refrigerants! Whatever possessed the industry to adopt a 500 psi refrigerant with field terminations is friggin beyond me, as you can find me bellyaching about in numerous other threads.

ChrisJ

archibald tuttle said:

think this is 100% so, but it begs the question: if you don't want a flare on the run because it is a potential leak point, why do you want a flare at the end? I believe the epa manual says that the average life of refrigerant charge is 7 years IIRC. i have to believe that flares are 90% or even 99% of the problem with 410 minisplits. i've got 50 year old refrigerators working fine on their initial charge. Now refrigerators, thankfully, don't use 410 but, more importantly no field terminations so they can even use flammable refrigerants! Whatever possessed the industry to adopt a 500 psi refrigerant with field terminations is friggin beyond me, as you can find me bellyaching about in numerous other threads.

7 years?

That's pitiful! And we all know where that limit is coming from and it's not the owners of the equipment or the refrigerant. Sure, you've got the typical dope that accidently drills or cuts through a lineset doing some repair or addition, but I highly doubt that's effecting that number.


The average life of a charge should easily be 20 years.

ratio

archibald tuttle said:

<snip>

…now comes expensive but sexy looking "flareseal" which is either so new or so useless that it has made very little market penetration. …

<snip>

You forgot choice #3: the things are just so darned expensive! IIRC it's 5-10 bucks for one ¼" warsher.

Protip: Do torque them properly. They will compress, so you might think they're going to seal, but they'll start leaking after a few days if they're not tight enough.

archibald tuttle

@ratio

i assume you are talking about flareseal although maybe you are talking about yet another offering? i was a little confused by the use of the carol merrill lets-make-a-deal motif, i won't say a precise number because specific prices are verbotten, but its a bit less than what you're thinking these days.

absolutely seems like a high cost for who knows what gain, but, if properly torqued they prevent the majoirty of currently experienced flare leaks they could cost 5 times as much and still be worth it.

on that topic, you'll note, i still want nylog on the threads (not because the threads seal but to allow the same amount of wrench torque to deliver high pressure to the flare surfaces.

ChrisJ

I do not believe there are rules against discussing prices of tools and many materials on the forum.
Especially those that are readily available in retail and on websites like Amazon.

mattmia2

I suspect the washer you put in a flare gives more material to deform and make a seal on an irregular joint where the distance between the cone on the fitting and the cone on the nut has a poor tolerance or the copper is already stretched thin from previous mating.

I don't think a properly made flare is a potential leak point any more than any other joint. I have a mini fridge that had an aluminum evaporator that I had to remove to fix a leak in it and I reconnected it with flare fittings and it has held a charge for around 15 years now. It has a piercing valve on it as well if I recall.

I think the 7 years is coming from the inability to manufacture copper tubing anymore.

ChrisJ

mattmia2 said:

I suspect the washer you put in a flare gives more material to deform and make a seal on an irregular joint where the distance between the cone on the fitting and the cone on the nut has a poor tolerance or the copper is already stretched thin from previous mating.

I don't think a properly made flare is a potential leak point any more than any other joint. I have a mini fridge that had an aluminum evaporator that I had to remove to fix a leak in it and I reconnected it with flare fittings and it has held a charge for around 15 years now. It has a piercing valve on it as well if I recall.

I think the 7 years is coming from the inability to manufacture copper tubing anymore.

Who isn't able to manufacture copper tubing?

mattmia2

I would assume China but I don't know how we got here, I just know I have a stack of 3 dehumidifiers where the refrigerant has leaked out through what should be solid copper tubing.

archibald tuttle

ChrisJ said:

I do not believe there are rules against discussing prices of tools and many materials on the forum. Especially those that are readily available in retail and on websites like Amazon.

Hey, im totally down with that but im walkin on eggs what with talking about refrigerant politics so im just trying to stay in good graces.and i thought i remembered that was the deal. I thought it was out of hospitality/consideration for manufacturers and distributors who provided some advertising support for the site not needing to have every thread devolve into how to beat this or that producer or supplier by 10 bucks (well add inflation).

I don't think that is really what was going on here on this thread in debating the general value proposition of various interventions against flare leaks, but just stepping careful.

pedmec

@archibald tuttle Because flares at the condensing unit and indoor head are accessible. Trying to find a joint in the middle of the piping is not always accessible. The manufacturers do not want any soldered or brazed joints on the linesets either for fear of contamination. Not even allowed to add filter driers.

ChrisJ

pedmec said:

@archibald tuttle Because flares at the condensing unit and indoor head are accessible. Trying to find a joint in the middle of the piping is not always accessible. The manufacturers do not want any soldered or brazed joints on the linesets either for fear of contamination. Not even allowed to add filter driers.

In other words.

They don't trust guys to flow nitrogen while brazing or to use flux in an appropriate manner when soft soldering.

pedmec

And on another note. We use refrigerant press fittings like Zoomlock all the time. Although very expensive it is very fast and limits the amount of possible oxide formation on the id of the pipe. In the Boston area and adjoining suburbs we also are required to pull permits and have a fire watch if we are to have an open flame. While the permit is self reporting you still need to have the additional fire watch. Sometimes the city or town will require somebody from the local fire dept or they will allow a tech within our company who is certified to act as fire watch. This just adds to the cost of the job that not every company is performing this service.

ChrisJ

@pedmec I guess HVAC guys and plumbers in NJ have had less dangerous accidents with fire than in your area.

  

pecmsg

ChrisJ said:

@pedmec I guess HVAC guys and plumbers in NJ have had less dangerous accidents with fire than in your area.

  

On commercial jobs fire guards/watch are required.

pedmec

@ChrisJ Maybe but the realty is we got caught in the firing line. Welder caused a fire and the state made a change that affected us. We are collateral damage

mattmia2

We had a building where they made us pull a burn permit for soldering audio connectors.

pedmec

Its not a bad thing as more a pain in the ****. I have talked to some friends in the field who don't even know its a requirement. They don't believe me when i say it and obviously ignore it as the just chalk it up to political crap. The hard part is competing with that mentality.

ChrisJ

I think I've heard it called a "hot permit" around here but I could be remembering wrong.
We were told we needed one for a chop saw back in 2006.

EBEBRATT-Ed

@pedmec depends on where you're working in some locations it's not enforced. We all had ti get the silly "certificate" years ago

pecmsg

pedmec said:

Its not a bad thing as more a pain in the ****. I have talked to some friends in the field who don't even know its a requirement. They don't believe me when i say it and obviously ignore it as the just chalk it up to political crap. The hard part is competing with that mentality.

Like LOTO if not used and something goes wrong guess WHO get the blame?

pedmec

@ChrisJ thanks, Couldn't think of the correct term even though at work we use the term everyday lol. Been out of work for a (PFML) while to help the wife.

archibald tuttle

pedmec said:

And on another note. We use refrigerant press fittings like Zoomlock all the time.

Forgetting the fire watch, I'm wondering if this is the wave of the future, even for minisplits. Currently the Flare connections on the units are usually part of the service valve so you can't cut them off and crimp. As I get ready to adopt some one of these press conventions after crowdsourcing the best choice available that fits my milwaukee tool, I am still a bit gunshy about the length these technologies have been widely in service and whether the seals are subject to degradation. Maybe this is the answer to the current 7 year itch that refrigerant seems to have for leaving the system.

@pedmec I get the difference between flares in undisclosed location hidden in a wall or ceiling in some line set vs. at known connection at the indoor or outdoor unit; but my point was, if flares are likely leak points and the industry is averaging only 7 year refrigerant life, I'm thinking that these connections might deserve a degree of reassessment.

I do think posters are right that they were trying to get around poor brazing techniques and risk of flame, esp. where indoor units are in the finished house potentially requiring connection near flammable materials or where there is the possibility. of introducing flame and heat into concealed spaces accidentally.

others have argued this short use life for refrigerant charge might be related to pushing the tolerances in manufacture and factory joinery of condensors, evaporators, controls or tubing as opposed to just poor connection. I continue to maintain that running refrigerants at 400 to 500 lbs. is an equal part of the problem. I will admit I don't have good access to review the industry's earlier results but most of the R-22 stuff i've worked on is holding charge at 20 years or better and, worst case is looking for a little top off.

That doesn't mean that, prior to elevated concern about refrigerant loss/discharge–and when R-22 was cheap, that my anecdotal experience counts as good statistics. But I continue to maintain that an industry focused on keeping refrigerant in the system was better served with R-22 and that improved professionalism coupled with more limited access to and higher costs for the refrigerant and R&D focused on R-22 could have given us a better generation of efficient minisplits with negligible ozone damage, better customer satisfaction, and even greater market penetration than all the subsidies in the world have now given us. But that's anecdotal me talking again.

pecmsg

Minis have 4 connection points. It's not that hard to make and seal 4 flairs!

ChrisJ

pecmsg said:

Minis have 4 connection points. It's not that hard to make and seal 4 flairs!

Flares are easy to make.

Easy is still too hard for many.

pecmsg

ChrisJ said:

pecmsg said:

Minis have 4 connection points. It's not that hard to make and seal 4 flairs!

Flares are easy to make.

Easy is still too hard for many.

Roosevelt Raceway, Your old enough to remember. All belt driven compressors. All the compressors were Flared to the line set, then 95/5 was used! Everything was R-12 including the ice cream freezer. That equipment ran for over 40 years.