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vinodvlimaye
17-02-2009, 11:42 AM
Sir,
I would like to use the PM1-40 OR PM1-50 OR ( PM3-40/PM3-50) valve for the following WATER CHILLING APPLICATION @ 1 DEG C OUT ,

1 the capacity of the plant is 45TR @ Nh3 gas, evaporation (sst) suction temp (-4 degC) , condensing (sdt) temp 38 degC,
2.Application is chilled clear water: in temp to chiller is 5 deg c & out from chiller is 1deg. Also note that the flooded chiller used in this application is welded cassettes heat exchanger WPHE.

We would like to maintain the constant evporative pressure (& hence the temp) in the WPHE to avoid the freezing of clear water in the channels when it comes out from the WPHE

Pl suggest which pilot operated valve we should use with PM-1-40 ? ( CVP/CVPP/CVT/CVQ/CVC ?)


Can you help me ?
vinodvlimaye (india)
NoNickName
17-02-2009, 12:23 PM
What brand is that valve?
US Iceman
17-02-2009, 02:44 PM
1°C chilled water is approaching an area where you run the risk of operational problems. A -4°C evaporating temperature adds to the potential problem.

Even with a back pressure regulator that holds a constant evaporating pressure.

This is really, really difficult to accomplish and work long term (successfully).:eek:
SteinarN
17-02-2009, 03:38 PM
I suppose some sort of flooded evaporator is the best solution in this case. And a generously sized evaporator having the necessary capasity at a relatively high evaporation temp like -1°C.
RANGER1
21-02-2009, 03:25 AM
Its a danfoss valve and you could use a PM3 with a CVQ and EVM solonoid in series . Measuring /controlling outlet water temp to modulate valve .
A water flow switch can be installed as back up .
If water flow switch and / or water temp to low , turn EVM off to stop refrigeration to prevent freeze up .
Compressor could also be shut down if dedicated to that system only .
Check with danfoss rep .
SURESH YADAV
21-02-2009, 06:06 AM
Hi... Vinod...
1. For Back Pressure regulating valve Model PM1-40/ PM1-50, the pilot valve is CVP(LP) should be used and it is purely mechanical valve.
2. For Back Pressure regulating valve Model PM3-40/ PM3-50, the pilot valve is CVQ with EVM coil should be used and it is electrical operated valve.
3. PM1 valve is cheeper than PM3 valve