Aircon pipes spanner size

[michael8554]

Hi all

I'm getting the tools together to install an ElectriQ 12000BTU DIY Split Aircon, delivery in 5 weeks time.

What size spanners do I need for the 1/4" and 3/8" flanged copper "compression" fittings ?

A simple enough question for google, but zero correct results, just loads of results for 15mm and 22mm fittings :-(

 

[Andy™]

adjustable should work. just make sure its imperial

 

[michael8554]

Thanks,
I generalised when I said "spanner".
The instructions require a torque wrench on the joints.
So I will need to buy open-ended imperial "crowsfoot" attachments of the correct size.

 

[Andy™]

you can do it without a torque wrench. you will need a vacuum pump though...

 

[poni]

some come pre-charged with gas and you purge the pipe work with some of this gas, the pipe work is fixed length for this to work,

 

[Andy™]

some come pre-charged with gas and you purge the pipe work with some of this gas, the pipe work is fixed length for this to work,

been a few years since i fitted one. they do come pre charged but you should vacuum out the air on the non sealed side before opening the valves. it'll also help find any leaks before you blow a larger hole in the o zone, although you're only testing at -1 bar so may not detect all leaks

 

[poni]

been a few years since i fitted one. they do come pre charged but you should vacuum out the air on the non sealed side before opening the valves. it'll also help find any leaks before you blow a larger hole in the o zone, although you're only testing at -1 bar so may not detect all leaks

100% right this is the best way , but this way takes skill, not a job for a DIYer , i was surprised the first one I fitted , cant remember all the instructions , but it did say something along the lines of" connect all pipe work to valves, then crack open pipe on one side and vent for so many seconds ( i think it was 2 sec) then tighten backup and open valve to set to work, real mickey mouse stuff , I remember doing the vac for 24hrs then letting the gas in (Freon 12 and 24 I think) its all band now of course

 

[johnb2713]

Hi all

I'm getting the tools together to install an ElectriQ 12000BTU DIY Split Aircon, delivery in 5 weeks time.

What size spanners do I need for the 1/4" and 3/8" flanged copper "compression" fittings ?

A simple enough question for google, but zero correct results, just loads of results for 15mm and 22mm fittings :-(

I'm surprised that you dont have to vacuum out the refrigerant lines to remove the air. Definately an imperial adjustable spanner is the tool of choice you can then guarantee the incorrect spanner size for all of the fittings.

Here's a guy installing one of these units.

 

[binky]

I would say vacuuming the pipe is important to remove any moisture. Last thing you need is an ice blockage, albeit a short piece of pipe won't have much moisture in it

 

[michael8554]

Thanks for all the replies.
I have a vacuum pump, as recommended in the instructions.
I also have an adjustable wrench.
I could tighten with the wrench and hope it's tight enough.
And not too tight.
Or too loose.
Or I can tighten to the recommended torque.
That's the sort of detail that could be left out of a "DIY Guide" if it wasn't that important.
But they include it.

So does anyone know the "spanner" size for 1/4" and 3/8" fittings ?

 

[Andy™]

I could tighten with the wrench and hope it's tight enough.
And not too tight.
Or too loose.
Or I can tighten to the recommended torque.

if its anything like the torque settings for MCB's etc you can torque it to spec all you want. cable will then most likely fall out because it wasn tight enough...

as with most things that need 'torqued' you can do it better by feel

and unlike an M6 bolt having a 10mm head, those fittings could have anything and may even vary within the same product range depenig what supplier / spec they used...

 

[michael8554]

"you can torque it to spec all you want. cable will then most likely fall out because it wasn tight enough..."

Tighten to torque.
Wriggle the cable.
Slightly loosen and then re-torque.
Won't fall out.

"those fittings could have anything and may even vary within the same product range "

Good point.

 

[johnb2713]

Thanks for all the replies.
I have a vacuum pump, as recommended in the instructions.
I also have an adjustable wrench.
I could tighten with the wrench and hope it's tight enough.
And not too tight.
Or too loose.
Or I can tighten to the recommended torque.
That's the sort of detail that could be left out of a "DIY Guide" if it wasn't that important.
But they include it.

So does anyone know the "spanner" size for 1/4" and 3/8" fittings ?

To be fair, how tight isn’t really an issue, you’re compressing soft copper onto hard brass, you’ll be fine. Up to shearing and back half a turn.

 

[roys]

I always find it reassuring to say the words click click when tightening things up, the virtual torque settings never fails

 

[michael8554]

Hi John

"Up to shearing and back half a turn."

What's shearing ?

Tight enough to snap the fitting ? ! ?

 

[Andy™]

or strip the threads

 

[michael8554]

No seriously, what do you mean by "shearing" ?

 

[johnb2713]

No seriously, what do you mean by "shearing" ?

Sorry, it's my Yorkshire humour kicking in there. It means tighten the nut until the threads strip or the fitting snaps then remove half of a turn.

Sorry

J

 

[Marvo]

Torque settings for HVACR flare nuts is important, it's soft drawn copper pipe so if you overtighten the flare nut cuts into the pipe at the base of the flare which can cause separation and obviously undertightening just means it leaks slowly. It's especially important with newer generation air conditioners that use freon 410A or similar gases because the pressures it runs at are far higher than the old air cons that used R22.

I have one of these, it's surprisingly accurate but not cheap;
https://www.amazon.co.uk/Yellow-Jacket-60624-Digital-Adjustable/dp/B0C3RSGL22


I'm sure this cheaper version would also work for occasional use.
https://www.amazon.co.uk/Kuphy-Digi...cf601126f7df391fa67038e0869aceb8&gad_source=1

 

[johnb2713]

Torque settings for HVACR flare nuts is important, it's soft drawn copper pipe so if you overtighten the flare nut cuts into the pipe at the base of the flare which can cause separation and obviously undertightening just means it leaks slowly. It's especially important with newer generation air conditioners that use freon 410A or similar gases because the pressures it runs at are far higher than the old air cons that used R22.

I have one of these, it's surprisingly accurate but not cheap;
https://www.amazon.co.uk/Yellow-Jacket-60624-Digital-Adjustable/dp/B0C3RSGL22


I'm sure this cheaper version would also work for occasional use.
https://www.amazon.co.uk/Kuphy-Digi...cf601126f7df391fa67038e0869aceb8&gad_source=1

I’m sure all of what you say is theoretically true, in practice however not really needed. I’ve just had £28,000 of AC installed in my commercial premises and all of the joints were tightened by the Armstrong method and an adjustable spanner. This was installed by an AC engineer who I have used over the last 30 years, not once has a pipe joint ever leaked or failed. My home installation consists of some 13 split Mitsubishi Heavy Industry units, again I only used an adjustable spanner and arm power.
The same style of connection is used on car brake lines where pressures of 10,000 psi and above are easily achieved, I don’t feel refrigerant gasses getting to the dizzy heights of 400 psi max are really going to test the materials or joint integrity to any great degree.
Only my viewpoint, I am an engineer but not an AC engineer and call on practical experience rather than a university theory book.