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SPR
19-06-2006, 03:08 PM
Can anyone tell me what symptons that would be likley to occur if the pipe runs to a remote condenser were to long, the problem i have is with Liebert close control units, i'm convinced that the runs are to long (about 75-90 Meters mostly verticle) there have been so many problems with these units that it would to many to list so i was wondering what sort problems would arise from the pipe runs being to long.

Paulajayne
19-06-2006, 03:13 PM
Hi

The most likely problem would be pressure loss.

This site is very useful:-

http://www.pressure-drop.com/

malik55
19-06-2006, 05:21 PM
If refrigeration piping is not designed properly with long runs you have pressure drop problem as Paulajayne said and also you will face oil problems.

US Iceman
19-06-2006, 06:14 PM
The pressure loss is only one part of the problem.

Excess pressure loss also affects the quality of the liquid flowing to the expansion valves. Without sufficient liquid subcooling, the refrigerant will flash off. This lowers the amount of liquid feeding the expansion valves and reduces the cooling capacity.

If the suction lines are not sized properly, you can loose the oil return back to the compressors, or have excessive suction line pressure loss. This affects the compressor capacity also.

It's not so much the piping length as it is probably due to improperly selected tubing diameters, poor installation of the tubing, and other contributing factors.

One other thing: Long suction lines can absorb a lot of heat if the lines are not insulated properly. The additional heat gain can increase the motor and discharge temperatures also. Neither of these are desired.

frank
19-06-2006, 09:19 PM
(about 75-90 Meters mostly verticle)

Thats some large building :eek:

SPR
19-06-2006, 09:34 PM
cheers guy's for replies, and yes Frank it is a very large buiding.

US Iceman
19-06-2006, 10:37 PM
I'm sorry to say I did not catch the "mostly vertical" part. That's a good call Frank.

If indeed the pipe runs are mostly vertical; which line runs up and which one runs down?

Each presents it own set of unique problems.

Renato RR
21-06-2006, 02:32 PM
Liebert Hiross?

Renato

Makeit go Right
22-06-2006, 06:37 PM
And, there possibly may have been a need for oil-trap bends on the climb, to help the oil get around. Worth getting a sketch off to the technical dept of Liebert, with pipe sizes and the height changes, and ask what should have been installed in this respect. Maybe nothing, but possibly they were needed.

{And maybe this aspect is nothing to do with your system's symptoms.}

Tiesse
20-04-2008, 06:45 AM
If it is a Liebert Hiross or Emerson Networ Power unit, your installation is outside of the manufacturers maximum pipe run recommendations of 50m. Any installation outside of this recommendation needs to be technically validated where you would be advised of the pipe sizes required & more than likely the need for an oil separator.

oby1
07-04-2009, 05:09 PM
If it is a Liebert Hiross or Emerson Networ Power unit, your installation is outside of the manufacturers maximum pipe run recommendations of 50m. Any installation outside of this recommendation needs to be technically validated where you would be advised of the pipe sizes required & more than likely the need for an oil separator.
Hello everyone,
I have a question about sizing route for a cold Emerson Liebert Hiross, HPM model S10OA.In technical specifications of products, we recommend a cold trail, diam.12 liquid, gas diam.12 up to 50 meters if it is my traseu.Intrebarea is ok or should I do the calculation based on the length?
Thanks in advance.

al
07-04-2009, 07:28 PM
you may want to insulate the liquid line to prevent (as iceman said) flashing off, is the sight glass clear under load? applies especially if the pipe shaft is warm.

al