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coldkeeper1
14-05-2008, 06:01 AM
Dear fellows:

There´s this old marine chiller I´ve been called to service, installed in a vintage 1950s-1960s patrol boat. The unit seems to be homemade since there are just a few pressure reading points both for the refrigerant and water sides. It exhibits three shell-and-tube evaporators connected to a screw type compressor. Water temperature as indicated in the gauge at the main outlet pipe is 49 deg F vs the required 44 deg F. I´ve been able to read the water temperatures at each evaporator water outlet and they read (in deg F) 44, 46 and 52. I´ve been informed that all of the evaporators have been recently cleaned internally. From pressure drop readings across the evaporators, all seem to be receiving the same flow of water. Before proceeding to get into the nightmarish job of accessing the absurdly hard to reach TXVs (there are three of them, feeding from a main liquid line, with two of them looking newer than a third one), I would like to hear your opinion on this theory: is it possible for the liquid refrigerant to choose going through the lesser resistance path across the seemingly newer TXVs than across the maybe obstructed or non operational older TXV?

The MG Pony
14-05-2008, 10:00 PM
A univeral law is every thing is lazy, it will ALL WAYs go the easiest route!