Copeland

Had a factory visit last Tuesday at Copeland factory Welkenraedt where they make the open compressor, semi-hermetic (the bigger ones) and the scrolls from 7 till.
Saw a horizontal running prototype of a dual 50 HP scroll (tandem) (motor had on both sides of the axes a scroll) and one scroll was modulated.

Hey all... learned there something I was not aware of it.
If you change a valve plate completely, how do you guys do this?
Describe it here because something is important and all of us can benefit of it.
I won't tell it straight away because there will be again (like always) guys who will say afterwords: 'Oh,... i knew this already a long time.'
We were with 10 techs and nobody heard of this before.
It has something to do with that little piece of gasket which is always coming out the cylinder head.

unfortunately i do not work on many open drive systems... :(

so i will wait until all is revealed peter :)

Hi Peter :)
would it be anything to do with using new head joints and a torque wrench. I have seen the bit in the middle blow out with liquid trapped, or in one case the power went off and the high load and possible liquid migration blew nearly all the joints on a pack.
Kind Regards. Andy. :) :)

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Originally Posted by Andy

Hi Peter :)
would it be anything to do with using new head gaskets and a torque wrench. I have seen the bit in the middle blow out with liquid trapped, or in one case the power went off and the high load and possible liquid migration blew nearly all the joints on a pack.
Kind Regards. Andy. :) :)

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Hello Andy,
It's indeed a fact that the small piece between LP and HP section under the cylinder head is very small and that is also that specific part that allaways will blew out first.
Now, it has something specific with the little piece of gasket that is always coming out the cylinder head.

If it's a model 6R it could be this: PLASTIC PAD USED WITH VAL-1561
Roger :confused:

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Originally Posted by shogun7

If it's a model 6R it could be this: PLASTIC PAD USED WITH VAL-1561
Roger :confused:

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Any model whereby valve plates can be changed.

Those who responded got the answer via private message.
I thought it was worth knowing it because it was something pure technical.

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Originally Posted by Peter_1

Those who responded got the answer via private message.
I thought it was worth knowing it because it was something pure technical.

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Oh Peter, you're such a tease! I promise not to say I knew it already.

"Now, it has something specific with the little piece of joint that is always coming out the cylinder head."

I can't even figure out what that sentence means!

Rog

I know Rog I'm a tease.
On the other hand, I do my best to explain myself. Perhaps not a bad idea to re-read the thread http://www.refrigeration-engineer.co...ead.php?t=1489 started in Tanzania.

Why others understanded it perfect?
Perhaps they ever replaced valve plates on Copelands?

I don't know.

Peter

In Dutch if it wasn't understandable.
Ik zal het de volgende keer voor de eentalige en meestal eigenwijze Amerikanen misschien best ook nog eens in het Nederlands schrijven zodat ze het dan misschien zullen begrijpen.

And if the Dutch wasn't understandable
Peu-être se sont seulement ceux qui ont remplacer déjà des clapets sur un Copeland qui savent que je veux dire et ce n’est pas une affaire de langue mai de compétence.

And that's all I know Rog
Leiter fur sie aber my künde von die tride Spräche is so schwerig das ich besser nich mehr sache.

Sorry, Peter, didn't mean to insult your language abilities. I have struggled to become fluent in Spanish for many years and it is a piece of cake compared to English with its roots in Latin, Greek, and Germanic root languages. I admire your English abilities.

Okay, what I should have said is: what is a "little piece of joint" and how does it "always come out of the cylinder head"? I have changed a few small HP Copeland cylinder heads in times past, but prefer a complete change-out now. Do you mean it comes out when you are changing the head? I didn't see any responses in the thread that nailed it; seemed like most, like me, were scratching their heads.

But by tease, I meant, you are making us beg for the answer.

No offense intended, please pardon my poor expression.

Rog

I will try to explain it: the next time you can grab a Copeland - any semi hermetic - have a look at the cylinder heads.
Between the head and the valve plate is the gasket (a joint is something completely I understand now thanks to Rog, edited previous posts joint is the French name for gasket) and you will see that a piece of gasket is coming out the cylinder head (half of a circle shape)

On that piece of gasket there is a number stamped on it. That number is somewhere the thickness of that gasket in thousands of inches (forgot to ask this). Sometimes, you must scratch carefully the paint away.

When they - at Copeland - assemble the cylinder head, they first measure for each compressor the spacing between piston and cylinder.

To be sure that they have the smallest clearance - so highest volumetric efficiency – and that each compressor leaves the factory according to the specs, they adapt the gasket for each compressor to that specific clearance.

So, if you receive your new valve plate, there are always spare ones in it. Well…that’s what I thought now for 20 years, that it were spare ones. But they aren’t. If you look at them, there are also numbers printed on it.
So you must search for the same number you had or that one that’s just a little bit thicker. If there was a thick one installed and you install a small one, then there is a change that the piston will hit the cylinder.

So that’s the story and I thought it was usefull, at least for some.

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Originally Posted by Peter_1

....When they - at Copeland - assemble the cylinder head, they first measure for each compressor the spacing between piston and cylinder. ...

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Ah, yes..... I do not work currently on any Copeland equipment. I have experienced the same thing twenty some odd years or so ago when I had the distinct pleasure of applying small, open Schnacke-Grasso compressors on small wineries using ammonia. These were the smallest compressors then available, "K-20" seems to come to mind as the model number?

When servicing the heads, and right now I do not recall why I was into the heads this often, we would place some soft lead solder onto the top of the piston and turn it over by hand. Then, that sqashed solder would by miced, and the head clearance adjusted to be correct. It was something of an anachronism at the time to have to do this step, as none of the other Fircks, Mycoms, Yorks, Vilters, Carriers, etc. required anything like this. My conclusion at the time was that it was a way of cheapening the manufacturing of the compressor, at the dubious expennse of having the field engineer/tech having to spend more time buttoning-up the beastie. :D I got rather good at ripping the head on and off for dozens of these compressors!

A most interesting explanation, Peter. Thank you! :)

The gasket blowing out seems pretty common between the cylinders. The newest version of Discus we put in had a bolt in the center of the valve plate to prevent this from happening. I believe you can modify the old valve plates to accomodate this hole so it doesnt keep happening. The comp body should already have the threads in it for the bolt.