Difficulty fitting tubing on discharge port

[kay86]

Hello everyone, noob here. It wasn't clear to me that the copper ends of the compressors used non-annealed copper, so when I started using the swaging tool on it to fit 5mm OD tubing on 4.95mm discharge port of my embraco compressor, I realized it was pretty hard so I stopped before being able to fit the pipe, however you can see that the end has become slightly larger. Now it's clear to me that I have to heat up to anneal the copper before using the swaging tool, but my question is, how do I know if I have damaged it? I will be using R290 so I am paranoid about everything and I just don't want to have the end splitting on me under the high pressure of the discharge port.

16256

[frank]

2 ways to deal with it.
1, swage your pipe out a little so that it fits snuggly, or
2, just fill in the gap with cupro brazing rod when you braze the joint

[seanf]

Could you use heat to relieve any stress created when the pipe was swaged?

It dosnt look like youve swaged it too much, so I'm guessing theres still a good wall thickness to the comps pipe and theres no cracks?

When youve done all your brazing on the system, give it a strength and leak test with nitrogen?

[kay86]

2 ways to deal with it.
1, swage your pipe out a little so that it fits snuggly, or
2, just fill in the gap with cupro brazing rod when you braze the joint

Thanks frank, I plan on using % silver rod for every joint in this project

[kay86]

Could you use heat to relieve any stress created when the pipe was swaged?

It dosnt look like youve swaged it too much, so I'm guessing theres still a good wall thickness to the comps pipe and theres no cracks?

When youve done all your brazing on the system, give it a strength and leak test with nitrogen?

Hi Sean, yes ofc I stopped why before I saw any crack and I also believe that heating to cherry red will help relieving evental internal stresses. I plan on charging to 225 psig with nitrogen which I believe is standard testing for R290 systems.

[frank]

Silver solder will not fill any gaps/cracks. Personally, with your situation, I would use a brazing rod

[kay86]

Sorry Frank maybe I'm unfamiliar with the correct term in english, but by silver solder I was referring to an actual brazing rod with 34% silver content and melting point at arount 700°C by the name of Castolin RX 8840 and it's a product used by HVAC professionals here in Italy.

[kay86]

Oh I understand, I think you meant me saying the silver solder used for electric components, no I would never use that with pressurized gasses, let alone flamable gasses. I know some people on youtube have posted some work of them using even lead solder in hvac systems and they often seem to hold prtetty well but I want to sleep with peace of mind and I only use what professionals use :)

[monkey spanners]

Have swagged compressor stubs without issue, the heat from brazing will remove any stresses you are worried about.
If you want to avoid swagging the pipe you can wrap some electrical tape round the pipe you want to connect to the compressor and clamp it in your flaring block, this will squash the pipe a bit smaller (may take a couple of goes with increasing amounts of tape) so it fits in the stub. Clean all the tape and any residual glue off of the pipe before brazing.

[vhchicken]

If it were me, I would call a professional to do it.

[Rob White]

.

Hello.

Those small compressors are designed to be copper to copper brazed so the
pipe out of the compressor has a copper coating for that purpose.

If you heat it up too much to open the end up you could damage the copper coating and
then prevent a good brazed joint.

You are using brazing rod with a 30% silver content so just braze it as though it was
a normal copper to copper and use flux.

Heat up the pipe, swage it and then braze it immediately so it does not heat up and cool
down too many times.

Use your brazing rod with flux and it will give you a good gas tight joint.

Rob

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[Rob White]

If it were me, I would call a professional to do it.

Hello.

That is good advice, most of us would never have thought of that :D

Rob

.

[Frikkie]

Someone sent me a set of 'Spin Swage' and 'Spin flare' tools from the USA but I guess they would be available in Italy. They work with a 18v battery drill and they're very good. They have several advantages to the older type flaring/swageing kit such as you don't need a clamp to hold the pipe and also they spin fast enough and make enough heat to anneal the pipe as they go. I thought they just a gimmick kind of tool when I first saw them but I've been surprised how much I've used them and how well they work. The only disadvantage I've found with them is that they can leave small filings / swarf in the pipe after use so you need to angle the pipe downwards before use or be prepared to manually clean the inside of the pipe if it's horizontal.

https://www.youtube.com/watch?v=iFOTxT1qkLk