Check valves:

Check valves

Failure to return or non-return valves can be found in the following positions:

Reversible heat pump circuit protection to prevent the flow through the expansion valve is not one cycle
Hot gas network to prevent gas entering another evaporator
When multiple compressors discharge in one capacitor, for prevention of condensation of fluid back in idle compressor
Where two or more evaporators work at different pressures, to prevent suction gas supplied in the cold

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Check valves