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freezy
25-01-2008, 12:03 AM
Evening all,

Does anyone know if there is a limit in pipe size or radius when bending pipes which carry R410A. I like to bend pipes up to 1 1/3" but i'm not sure if it is permissable with the higher pressures.

Is there anything wrote in any regulations?

If a system carrying R22 has a HP set at 400 - 450 psi then this is not far off the operating pressure of R410A, to me this makes it okay.

Regards

Thermatech
25-01-2008, 12:29 AM
Freezy
When you form a bend with pipe benders the outside of the bent tube is pulled & stretched out so it gets thinner in wall thickness.
Tube manufacturers know that & build in a safety factor to allow for tube forming.
You need to get data from the copper tube manufactorers.
HP switch setting for most 410a systems will be well over 40 bar / 600 psi. Lots of splits & VRF pressure switch specification is 41.5 bar cut off pressure.
You might also find that with this type of pressure you can use standard gauge wall thickness copper tube up to 3/4 inch diameter but any larger size tube & you may need to start looking for heavy duty wall thickness tube.
Some UK distributors stock upgraded wall thikness tube on the larger sizes for the higher preesure 410a applications.

Thermatech
25-01-2008, 12:39 AM
freezy

What psi pressure strength test will you carry out to test integrity of the installed pipework installation ?

freezy
25-01-2008, 11:36 PM
Hi Thermatech

We pressure test to manufacturers spec, normally 38 bar. British standards want 1.1 x operating pressure and 1.3 x operating pressure for a strength test.

With the wall thickness thing, all pipe sold in the UK has to conform to British Standards and should have the correct SWG for this.