Refrigerant pipe bends

[bobjob]

hi all

I carry out maintenance work on the Air Con, equipment at a large industrial site,

A new company has started to install equipment and I have noticed that all of there pipe bends are not formed correctly !

The pipe sizes used are 11/8, 7/8 and 5/8
It seems that on the inside curve of the bend there is a bad ripple effect whilst the outside curve of the bend is good and smooth.

Has anyone else seen this problem and what if any,is the long term effect for the new installed equipment.

After they have installed the A/C systems, it will be up to me for the maintenance.

regards Bobjob

[NoNickName]

Yes, seen this a number of times. Usually when this happens, the copper was too hard (raw copper) at the time the bend was formed or forged. In the long run, the foldings will crack and leak

[jamcool]

Find out what type of bender are they using,someone is in a hurry

[US Iceman]

If the copper is soft drawn tubing and the correct bender is used, both the inside and outside radius should be smooth.

If they are using hard drawn tubing, the tubing will kink in the inside radius.

[Peter_1]

Well, we sometimes use half soft - or half had like you wish- copper, the straight ones so that you can install these much more nice looking.
The ripples inside the bend are then normal and this will cause no problems.
At least that's my experience.

No that we're talking about it, what can be wrong with the nibbles in the bend? I could not find one reason, only a litlle bit oil stagnation in the nibbles but this will be flow away if flow/speed is correctly sized.

Perhaps even an advantage when bending with a bender instead of soldering: the radius is much larger, so less pressure drop

You already had a prejudice when posting your post. I have noticed that all of there pipe bends are not formed correctly ! So you posed a not neutral question here whereby the possible answers could be expected in some way.

1 1/8 is not so common for bending on-site, we do it only till 3/4.

[Andy W]

From experience, when using Rothenberger stand benders with the adjustment roller for the slipper, if the slipper was too loose it would ripple, just right, it wouldn't. I use an ancient set of Hilmor benders I had given to me 8 years ago, go steady and they bend perfect, rush and it may ripple.

[dogma]

The guys at the Kembla factory told me to make sure you wash your pipe benders with soap. If there is oil on the benders they can slip a fly Sh.it and will cause the "ripple effect". <- Sounds like a triller movie title.
Some guys will oil all of their tools. I even saw a guy wiping his multi meter down with RP7.

[Paulajayne]

Hi

There are two main faults when bending copper on a machine -

1. Throating on the inside of the bend -caused when set too tight.
2. Ripple on the inside of the bend -caused when set too slack.

http://www.cda.org.uk/Megab2/build/p...20throating%22



Paula