Leaking Rotalock

[Grizzly]

This one would fit either the Industrial or the Supermarket sections.
Anyway I must be going through one of my "Lucky" periods.

Are you sitting Comfortably!!!
Basically I was working on a Bitzer pack with three screws,changing the oil filters.
This pack suffered a major leak recently.
It was one of those sites where you get the "we have done nothing" Answer!
( now please wash your hands after visiting the toilet. Is in 5 different languages!)
Anyway none of us could find the leak and having been recharged. Has been running OK for several months!

So I am kneeling on top of the pack, between comp1 and 2. Shutting the discharge valve.
When I shift my weight from one knee to the other, (as you do!)
I put out my left hand to balance, touching the liquid line going into the Economiser port on comp1.
The pipework moves, it is loose!!!
Basically what I discovered is whenever comp 1 is running and has reached a evaporating temp below approx -30c.
Its economiser port rotalock was contracted enough to make it loose and leak!
Whenever it warmed or unloaded pipework became rigid and gas-tight.

Like I say another moment of pure luck!
Although Monkey Spanners and others have touched on similar stories.
I felt it was worthy of mentioning as I am sure similar will happen again to someone!
And someone may "benefit from the story.
Cheers Grizzly

[nike123]

Nice one! I will try to remember it.

[monkey spanners]

I found this while looking for tightening torques for valves and meant to post it but can't remember if i did now....

www.ecopeland.com/literature/eCopeland/EN_Scroll%20replacement%20Guidelines_0.pdf (http://www.ecopeland.com/literature/eCopeland/EN_Scroll%20replacement%20Guidelines_0.pdf)

Makes interesting reading, copeland recomend thread lock on the rotalock threads.

I want one of the special tools but have yet to see one for sale anywhere :D

Jon

[nike123]

Some advise given to me when I was started in this trade and first time saw rota-lock.

When opening and closing them, engineer should first loose stem nut by 1/2 turn and then manipulate valve.
Then when manipulation is over, stem nut should be tighten again for 1/2 turn.

That reduces wear and tear at stem and reduce leak at stem to minimum.

[Grizzly]

Thanks for the input guys. I tried to delete the post this morning as reading it again seems a bit self indulgent.
For some reason it would not clear?
Anyway I went back to the site today.
When everything was nice and cold.
I checked all three rotalocs.
Guess what the other 2 nipped up.
In fairness this plant has been running for nearly 6 years.
With all the expansion and contraction that the valve has been subjected to.
I am not surprised they had loosened a little!
Lovely little screws but Harmonics may be an issue.

Thanks for the tip Nike.
I agree with you MS the crows foot I understand, but what is that they are using to counter-lock the valve.
Looks like something that has been fabricated?
Grizzly