Why braze refrigerator compressor fittings?

JackW

Our Jenn-Air double-door refrigerator makes a noticeable growling sound when the compressor turns on. It doesn't always do it, but when it does, we give it a little shake, and it stops. I suspect the compressor is starting to go out. I want to change it, but why must the connections be brazed instead of soldered?

Thank you,
Jack

JUGHNE

The compressor stub outs are possibly copper coated steel and some of the tubing in frigs are all steel.

Also soft solder may not handle the pressure and temp of the discharge line.

Others will know better than I, having never changed out a comp that small.

pecmsg

ASHRAE requires brazing on all refrigeration systems. 

There are silver bearing soft solders but they’re for special locations and the discharge line is not one of them. 

mattmia2

You can use flare fittings.

There are numerous theories about why soft soldering is not allowed from performance in a fire to flux in the sealed system. There are several threads here on it.

Are you sure your noise doesn't have to do with deterioration of the bushings under the compressor or other things rubbing somewhere?

pecmsg

mattmia2 said:

You can use flare fittings. There are numerous theories about why soft soldering is not allowed from performance in a fire to flux in the sealed system. There are several threads here on it. Are you sure your noise doesn't have to do with deterioration of the bushings under the compressor or other things rubbing somewhere?

You’re still going to have to brazein a Flair Stub on the compressor 

JackW

@mattmia2, I'm unfamiliar with flare fittings; I'll have to look into those. Are they an alternative to brazing?
Good question; I'm not sure it's not the bushings. I'll have to take the back cover off and look at them. Thanks.

JackW

@pecmsg, is that used to fill the compressor?

mattmia2

pecmsg said:

mattmia2 said:

You can use flare fittings.

There are numerous theories about why soft soldering is not allowed from performance in a fire to flux in the sealed system. There are several threads here on it.

Are you sure your noise doesn't have to do with deterioration of the bushings under the compressor or other things rubbing somewhere?

You’re still going to have to brazein a Flair Stub on the compressor 

why can't you just flare the stubs on the compressor and attach them to a flare unions?

pecmsg

mattmia2 said:

mattmia2 said:

You can use flare fittings. There are numerous theories about why soft soldering is not allowed from performance in a fire to flux in the sealed system. There are several threads here on it. Are you sure your noise doesn't have to do with deterioration of the bushings under the compressor or other things rubbing somewhere?

You’re still going to have to brazein a Flair Stub on the compressor 

why can't you just flare the stubs on the compressor and attach them to a flare unions?

Not enough stub. 

JackW

@mattmia2, I know what you mean by a flared fitting, similar to what is used on car brake lines; I've done those before. Are you allowed to use them on compressor fittings?

mattmia2

JackW said:

@mattmia2, I know what you mean by a flared fitting, similar to what is used on car brake lines; I've done those before. Are you allowed to use them on compressor fittings?

Yes, but you don't have to use the internal type fitting that they use for brake lines or double flare it, you can use a single flare and this type of fitting and nut:

https://www.supplyhouse.com/Bluefin-FLU025-1-4-Brass-Flare-Union
https://www.supplyhouse.com/Bluefin-FLSN025-1-4-Brass-Short-Flare-Nut

The pressures in refrigeration are lower than in a brake system and the vibration is less.

HVACNUT

Assuming you replace the compressor, do you have a vacuum pump, gauges, a micrometer, scale, and refrigerant? R134A?
But if the noise goes away when you assault the refrigerator, I would lean more towards a compressor mount (there's usually rubber bushings, sleeves, and bolts) being loose, or just a vibration somewhere. 

pecmsg

mattmia2 said:

@mattmia2, I know what you mean by a flared fitting, similar to what is used on car brake lines; I've done those before. Are you allowed to use them on compressor fittings?

Yes, but you don't have to use the internal type fitting that they use for brake lines or double flare it, you can use a single flare and this type of fitting and nut: https://www.supplyhouse.com/Bluefin-FLU025-1-4-Brass-Flare-Union https://www.supplyhouse.com/Bluefin-FLSN025-1-4-Brass-Short-Flare-Nut The pressures in refrigeration are lower than in a brake system and the vibration is less.

https://www.mfcp.com/product/fittings/industrial-45-degree-flare

JackW

@HVACNUT, yes, I do; I replaced the A/C system in my 2004 Buick Ranier and repaired a line break in a small refrigerator in my work room. I've never replaced a refrigerator compressor, though. I got a quote from a national appliance repair company; they wanted $1300.00 to replace the compressor.

I'm going to take another look at the mounting system. Thanks.

JackW

@pecmsg, thanks for the links. The factory compressor has two lines on the right side and one line on the left with a service port. So I can cut the old compressor out, then install the new one using the flared fittings on all the lines instead of brazing them.

JUGHNE

My "second" refg is a 1981 GE. It has had those sounds for the last 20+ years.

If I am near it, I just shake the whole fridge and it quiets down.

If the cond coil is plugged it will growl more so.

Only changed the cond fan motor and maybe the light bulb since buying it back then.

Those were the last good years for most appliances. IMO

JackW

@mattmia. Thanks for the links. I used Suppyhouse extensively when I redid my radiant heat system in my Morton building. Good company. The compressors I've seen online don't come with a service port. Where do I get those? Can I use a flared fitting, or must it be brazed?

ChrisJ

Just be cautious.
Often when a compressor fails it blows all kinds of lovely stuff throughout the system.

Do they make suction line filters for small equipment like this?

pecmsg

JackW said:

@pecmsg, thanks for the links. The factory compressor has two lines on the right side and one line on the left with a service port. So I can cut the old compressor out, then install the new one using the flared fittings on all the lines instead of brazing them.

Those stubs aren’t long enough to flair. 

JackW

@JUGHNE, Encouriging to hear. Our Jenn-Air is about 15-17 years old. We had a small leak in one of the lines several years ago; otherwise, it's been a good fridge.

JackW

@pecmsg, I'm confused; if they are not long enough, how can I use a flare fitting? Here are some pictures of one of the compressors I am looking at, along with the hardware that comes with it. What are the silver sleeves for?

HVACNUT

JackW said:

@pecmsg, I'm confused; if they are not long enough, how can I use a flare fitting? Here are some pictures of one of the compressors I am looking at, along with the hardware that comes with it. What are the silver sleeves for? 

I don't think you can. Once you cut off the Female ends of the stubs, there's not enough room for a nut and the flaring block.
The sleeves are for the mounting bolts.

pecmsg

JackW said:

@pecmsg, I'm confused; if they are not long enough, how can I use a flare fitting? Here are some pictures of one of the compressors I am looking at, along with the hardware that comes with it. What are the silver sleeves for?

You can’t without brazing in a stub. At that point braze in the lines. 

JackW

@pecmsg, have you ever heard of LOKRING NAV Connections?

JackW

@HVACNUT, ahh, that makes sense. Thanks.

JackW

@pecmsg, can you use MAP gas and OXY to braze?

ChrisJ

JackW said:

@pecmsg, can you use MAP gas and OXY to braze?

Yes especially lines that small.

A turbo torch on propane alone will probably do it.

EBEBRATT-Ed

@JackW

What type of refrigerant is in the system?


If you go to JW Harris web site (they make solder and brazing rod) you will see where they say soldering (use Stabrite #8 which solders just like plumbing solder) that using Staybrite is stronger than brazing. This is because brazing anneals and softens the tubing.

That being said,the reason brazing is preferred and some codes mandate it is because of the lower melting point of solder. Brazing rod is about 1000 deg and solder is around 550 degrees. If there is a fire the solder can melt and release refrigerant which can endanger the firefighters.

You can easily braze those joints with a small propane torch. Just pick up a MAPP gas cylinder. Most hardware store (at least decent ones) have MAPP gas and you can use the same torch.

Brazing is just as easy as solder. I would not use flares. You don't have enough room on the stubs.

JackW

@ChrisJ, thank you, I appreciate your help.

JackW

@EBEBRATT-Ed, Thanks for the info; I'll check them out. I have a small MAPP gas and Oxy setup that I have used around the house a couple of times. I have copper brake lines lying around; I'll give it a go when I get the proper rod. Thanks again.

JackW

@EBEBRATT-Ed, I checked out JW Harris's web page but found no Stabrite #8. I did find Dynaflow and Stay-Silv 15 rods. For the first one, you don't need a flux; for the latter, you do.

JackW

@EBEBRATT-Ed, I found it. So it's a soldering product, not a brazing product. What diameter do you suggest?

mattmia2

pecmsg said:

You can’t without brazing in a stub. At that point braze in the lines. 

I don't necessarily agree with that, it could be easier to braze on stubs and trickle nitrogen/co2 out in the open without catching the cabinet on fire then tighten up flares inside the cabinet.

There are also press type and sharkbite type refrigeration fittings. The tooling is prohibitive on the first and i wouldn't expect the second to be leak free over the several decades that the refrigeration system should last.

Oh, and you might be able to use a spin type flare tool on the stub and have enough room for the nut although that is kind of a big gamble for the cost of a compressor.

JackW

@mattmia2, thanks for the info. Lots to take in.

EBEBRATT-Ed

In this case you're talking small diameter tubing most of it looks like 1/4" or 3/8" od even 1/2" od doesn't take that much heat to braze.

Stay silv-15 is better than Dynaflow.

With a small system like that if it is R-134A I would just use Stay Brite#8

Again, what refrigerant are we talking about?

EBEBRATT-Ed

I am going to give an example of the "always braze all the time mentality"

We were hired to install some Trane split systems R-410A. We did not own the equipment but were hired to install it. We brazed all the piping while trickling Nitrogen or Co2. except the last suction line connection. Trane was on site to do the start up.

The suction line connection was to connect to a factory installed Refrigeration ball valve inside the condensing unit I believe it was 1 1/8 maybe 1 3/8.

Now a valve like that is going to take a fair amount of heat to braze. One side of this valve was right up against a partition panel in the unit. Trane should have provided a factory stub out on the valve but did not.

It was not possible to braze this valve without cooking it. One side was obstructed by the panel so you could not get a torch on that side. I had visions of the braze freezing on that side and not flowing around the valve and the amount of heat it would take would have damaged the valve.

3 ways out:

1 Cut out and patch the welded in partition or

2 Remove the charge, cut the pipe on the other side of the ball valve so it could be put back in with a coupling and braze a stub on the valve in outside the unit in a pipe vise, evacuate, recharge and change the dryer. Or

3. Stay Brite a stub into the valve as it sits


I left it up to Trane and they told me to Stay Brite it. The customer didn't want the panel cut and patched in a new unit. Trane's service tech also doubted the ability to braze it without cooking the valve.

and cutting the panel or removing the charge would have voided the warranty.

Should everything be brazed if possible Yes

But a lot of guys use stay brite and they sell a lot of it,

Any time you make hard and fast rules they don't cover every situation.

pecmsg

EBEBRATT-Ed said:

In this case you're talking small diameter tubing most of it looks like 1/4" or 3/8" od even 1/2" od doesn't take that much heat to braze.

Stay silv-15 is better than Dynaflow.

With a small system like that if it is R-134A I would just use Stay Brite#8

Again, what refrigerant are we talking about?

I hope its R-134A
Newer units are R-290 Liquid Propane! A hole new ball game out there.

ChrisJ

pecmsg said:

EBEBRATT-Ed said:

In this case you're talking small diameter tubing most of it looks like 1/4" or 3/8" od even 1/2" od doesn't take that much heat to braze.

Stay silv-15 is better than Dynaflow.

With a small system like that if it is R-134A I would just use Stay Brite#8

Again, what refrigerant are we talking about?

I hope its R-134A
Newer units are R-290 Liquid Propane! A hole new ball game out there.

I've seen R600 , Isobutane but not propane in any OEM appliances.
Why exactly is this a whole new ball game? It behaves much like R22.

It's flammable so you need to put your big boy pants on, but other than that, same ball game.

pecmsg

I worked on one yesterday, and as I was sliding the condensing unit out from underneath all the lines were hanging up. The water heater was right next to this refrigerator. Adeleine cracked or broken. I can’t even imagine what would’ve happened!

ChrisJ

pecmsg said:

I worked on one yesterday, and as I was sliding the condensing unit out from underneath all the lines were hanging up. The water heater was right next to this refrigerator. Adeleine cracked or broken. I can’t even imagine what would’ve happened!

How big of a charge of propane was in this refrigerator?

pecmsg

6.5 oz