Jinu117s Braided Suction line construction

[jinu117]

Brazed one up last night. Will make a guide when I have some time in my hand

[jinu117]

Guide for Making Stainless Steel Braided Suction line.

Tools required: Basic tubing tools, Brazing tools. Ultrasonic part cleaner (semi optional)
Solder: I use silver 45 for these. Lower silver content can be used but you better get your skills readied up for decent looking job
Parts: flexible suction line (I assume you know how to braze one up or can get it), Braided Stainless steel fitting the size, copper reducer.

Part 1. Preparation.

First of all involved parts picture... I ran out of reducer and I am not driving out today So I will only do one side.


I cut braid length about 2" longer than flexible part of suction so about 1" on each side can overlap some copper part of suction line. Than you place suction line in it. Be careful as cut end of braided suction line can be very sharp and you can hurt yourself.


Now here is the trick. I tried doing brazing differently but didn't like the look of it at the end. It was not a bad braze, it was just the way it was assembled. After few minutes how people do induction brazing hit my mind. So, I cut small piece of my 45 solder, wrapped it around the braided portion, put some flux on the solder itself. Make sure the solder can snugly fit on reducer... not too lose



I don't think next step will be necessary for seasoned people... but here it goes

[jinu117]

Part 2. Brazing.
Rule of thumb on brazing... cleaner the material, easier it will be when you want to get high quality (both in looks and mechanical strength). So clean clean clean.
I put thin coat of flux on entire reducer and put it to my braze stand.
Sorry for dark picture forgot to pop flash.

Here is order of brazing... you heat up the top part of reducer and suction line copper... Braze that part up. You don't need to completely braze around as this is just to hold two pieces together but might as well for looks. It doesn't make difference in time consumed anyway (and if you heated up good, it should flow around anyways)
Once done, you move the heat to section of reducer where the solder will be sitting snug against reducer inside. This will melt the solder inside and braze braided flex line to inside of reducer.

not so pretty eh? But you can clean it up easily...


One big important thing I noticed. I noticed suction line stainless steel not liking flux. Any residual flux has tendency to eat through stainless steel suction line we have once it has been brazed. On regular suction line, this is easy enough to make sure that none remains with enough elbow grease. But due to nature of braids... it will be nearly impossible to take them all out. Here is what i use (I use this for evaps, suctionline, etc anyway to do finial finishing or cleaning off the flux)


And once you are done drying off of course the time to do the elbow and grease of cleaning off

All finished part is at the top

[jinu117]

Space reserved for guide #3

[n00b 0f l337]

Hmmmm can't wait to see, I hate brazing to steel, huge pain in the bum.

[wdrzal]

How did you anchor the braid,I don't see any braze around the bottom where thr braid meets the copper?

[Pete]

Wow thats about the 1st decent bit of brazing i've sene in the phase game..sorry to say it. Also nice job on the cleaning up of it

[lross78550]

i hope thats part of my v2000 ss that your building
Lee

[boshuter]

Can you give some ideas or links on where people can buy the flexible line and the SS braid? I've found some SS braided lines ready made, but the regular flexible lines are very hard to find.

[jinu117]

Can you give some ideas or links on where people can buy the flexible line and the SS braid? I've found some SS braided lines ready made, but the regular flexible lines are very hard to find.

Only place I have in my links are by 100ft or 500ft roll. Let me search around a little. (yes I do get them by that quantity)

[SiGfever]

Is that an ultrasonic bath?

[jinu117]

Yes SiG... and harborfreight or e-bay has them at decent price quite often... I actually got it to clean my glasses... but it became parts cleaner :P

[[486]]

menards has 1/2 inch courrigated sst tubing in 25 foot rolls for less than $40, and 50 footers for about $80, and they also have 100 foot and 325 foot rolls, just remove the yellow-orange coating

and someone will say that it comes in 45 inch pieces, just look for the large coils near the hard copper tubing and iron pipe

[menards is a large chain hardware store in the midwest of the USA, just look in your local hardware stores]

[[XC] mysticmerlin]

Very nice jinu117 keep up the good howto. I like the braid to cover the flex but why if you have to cover it anyways?

[jinu117]

Reason for it is quite simple. The best corrugates SS flex I've seen (one I am using) is rated for 180psi working pressure and 280psi test.
Most of same size (especially ones in mach unit adn vapo unit), 1/4 nominal id and 1/2 nominal OD, are only rated for 115 psi working and 160psi test.
Now, the ones that are slightly larger 3/8 nominal id and .65 nominal od... have 60 to 100 psi working pressure and gets worse as it gets larger (bigger surface area).
For something like cascade, this could become big booboo if something fails in system without braid. what braid does it hold the line's expansion while when bursting happens, contain it. Once braided most of lines get about 10x the pressure ratings due to this.
You don't want suction line to be pressure relief point really..

[[XC] mysticmerlin]

got ya, that is why I ask. Like in the chiller section most are using the Tygon tube and then putting a 1" of ins on it when heater hose is a much better choice .
Thanks and like I say. Good howto. Keep it up.

[wdrzal]

The corrugated inner ss inner tube will grow in length when its pressurized without the outer braid.

[[XC] mysticmerlin]

the braid will stop the growth from happening? it does not look like it is "pulled" to it's max to hold it. just to dress it up.

[jinu117]

the braid will stop the growth from happening? it does not look like it is "pulled" to it's max to hold it. just to dress it up.

It is not to max maybe lol... i might need hydraulic tool to do that :P The part it looks thin is because it is actually holding on to copper 5/16 line which is thinner than 3/8 OD of the suction line... Besides, it can't just expand beyond braid as braid is basically clamped on both end

[wdrzal]

No need to "Dress it up" as the whole line gets covered with insulation.

without the outer braid the inner tube can grow by severial inches depending on wall thickness and internal pressure.

[[XC] mysticmerlin]

Is there a better choice than braided + flex for pressure situation's I.E. cascade's / auto CC ? For a normal SS is just flex ok? sorry to crap on your howto jinu117 but I find this important to ask.

[wdrzal]

Jinu. sort of sad all your nice work gets covered with insulation. But nice job and guide.

[jinu117]

Is there a better choice than braided + flex for pressure situation's I.E. cascade's / auto CC ? For a normal SS is just flex ok? sorry to crap on your howto jinu117 but I find this important to ask.

It's quite all right. I reserved some space for guide in ahead as I expected QA down the line... in fact, one day when there is enough, I might organize it and put it in on my 3rd place holder.
For normal SS... I prefer my 180/270 as it will NEVER reach that pressure
In fact, most cascade won't even stress it if it is working fine. It's when things going bad. If your suction is reaching 115 psi of mach units... you can figure out what temperature evap will be at.... hopefully, something turned it off or your computer turned off taking away any more load. The worst time for single stage is after prolonged load situation and turning it off. Since compressor is quite hot and so is condenser, static pressure will be much higher than typical 50-70 psi we usually talk about. Now for some heavily charged unit, the number might be approaching the 115 psi... but hopefully not quite there.
For regular SS, if you have something that is 1/4 ID and 3/8 OD (nominal) for suction line, you should be fine. If you do have something larger... it might not be good for prolonged usage.

And thanks walt I don't care if it goes in insulation or not... my customer deserves the best I can do

[[XC] mysticmerlin]

Jinu. sort of sad all your nice work gets covered with insulation. But nice job and guide.

That is why I asked, to cover up a very nice job is just , well , wrong but I guess it is needed.
Ok, I will leave it be for now. Keep up the good job jinu.

[VulgarHandle]

need to find some clear insulation