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lana
18-11-2005, 09:05 AM
Hi there,
I always use Danfoss TEV and they suggest that the TEV must be installed in a position that the liquid goes out from up to down. Also they suggest that TE2 models can be installed in a horizontal position but the vertical part to the distributor must be greater than 7xOD.
In an ALCO instruction I found that they suggest that the TEV can be installed in any position? :confused:
I far as I know the mixture of liquid and gas comes out of the TEV and the liquid must be distributed evenly through the evaporator circuits. Therefore, the liquid must be directed from up to down.
Any suggestion?
Cheers.:)

chemi-cool
18-11-2005, 02:54 PM
Follow the Danfoss instructions.

Chemi:)

US Iceman
18-11-2005, 04:55 PM
Hi lana,


... but the vertical part to the distributor must be greater than 7xOD

I do not understand what this statement is supposed to mean. What are you considering the "vertical part" of the distributor? What is the 7 times the pipe OD used for? I know this is for referencing a location point, but for what?

I think the preferred installation is to have the TXV feeding down into the distributor. By using gravity, the liquid is evenly distributed into the distributor itself. However, if the distributor orientation is upwards, the flash gas will distribute better since vapor rises.

In the literature the manufacturer will state a "preferred" method, but when you look at some applications (like a refrigerated display case for a supermarket) the TXV's are laying on their sides with the distributors horizontal.

I have seen distributors in all three positions (flow top to bottom, flow bottom to top, and horizontal. They all seem to work OK.

The important thing to remember is "if the manufacturer has a preferred installation method", you should use their information. There may be some specific requirement for their component.

Peter_1
18-11-2005, 06:28 PM
Something else now, equalizing line after of before the bulb?
And why?
These days, there's no leakage anymore between the internal stem, a TEV is in py opinion a high precision piece of mechanic, so there's no liquid injected any longer along the equalising line to influence the bulb.

And if there should be liquid injected along this way, then the bulb will sense this and close the valve, preventing liquid slugging to the compresser, so a safe situation.

But, complete the other way as prescribed by Danfoss.

This is what an experienced tech once told me.

lana
18-11-2005, 07:07 PM
Hi lana,



I do not understand what this statement is supposed to mean. What are you considering the "vertical part" of the distributor? What is the 7 times the pipe OD used for? I know this is for referencing a location point, but for what?



This means the vertical distance between TEV and the inlet of the distributer if the TEV is installed in horizontal position. This is specified in every Dandoss TEV packaging and in their technical bulletine.
About the Peter1's question I should say that the equilaizing pipe should be after the bulb in case there is an internal leak in the TEV. This is also suggested by Danfoss.:)

Peter_1
18-11-2005, 07:22 PM
Right, you have a serious leak between the internal stem of the TEV, something is broken inside.

You have monuted the TEV the way like Danfoss is saying.

Via the equalising line liquid is injected in the suction - and the bulb doesn't feel this because he's mounted in front of it - so the compressor sucks liquid, oil begins to foam and no sufficient lubrication any longer.

botrous
18-11-2005, 10:05 PM
Take a look at this Lana . . .

http://www.sporlan.com/10-11.pdf

hope this helps

Regards

US Iceman
18-11-2005, 10:15 PM
This means the vertical distance between TEV and the inlet of the distributer if the TEV is installed in horizontal position

That makes sense. If the TXV is installed horizontally and the distributor is installed vertically, there is an elbow between them for the change in direction from horizontal to vertical.

The 7 X OD is to allow the liquid to gain a uniform flow pattern after leaving the elbow, before the liquid enters the distributor. ;)

On the other points, I agree 100% with Peter.