Supermarket rack oil reservoir question

[friocold2008]

Hello people. Hope someone can clarify some doubts I have about the operation of the oil reservoir in a parallel compressor rack.
From what I can see in this rack, the oil reservoir is located between the oil separator (high side) and crankcase oil level controls (low side). According to the rack ´s manufacturer manual, return oil system is always kept at a pressure slighty higher than that in the compressors crankcases in order to keep the oil flowing from the reservoir into the compressors. But how can this be? Whenever the oil separator float valve cracks open, the pressure in the reservoir, connecting piping and oil level controls must be the same as the high side, correct? Does this high pressure ever reaches the crankcase or suction manifold? Any comments appreciated.

[D.D.KORANNE]

1) oil reservoir will have a pressure reducing valve which will vent the refrigerant to suction line header
2) oil separator outlet (oil) line will have non-return valve . This line feeds oil to reservoir .

Trust this will explain .

[4 evr learnin]

We use a product called "Trax oil" which is a float level controlled, modulating valve with an internal reducing orifice. I have found these to be quite reliable, with a fine tolerance to most copeland compressors! Also a lot less hassel than a pressure regulated oil reseviour or a float valve !