The Oil Stop Valve opens during start up to ensure lubrication
and cooling of the compressor and blocks the flow of oil to
the compressor during shutdown, thus preventing the discharge of
oil through the compressor inlet pipework. The pilot port must be
connected to compressor discharge upstream from the minimum
pressure valve and preferably to the wet side of the separator. The
inlet port must be connected to the downstream side of oil cooler
and thermal valve to provide 5 and 8 PSI respectively between
the pilot and the inlet.