🔍 Key Concepts

• Push/pull liquid recovery – one line must carry liquid from the chiller to the storage tank, and a separate line must carry vapor from the tank through the recovery unit back to the chiller • On the illustration, identify which numbered valves are on the storage tank, which are on the recovery unit compressor/condenser, and which are on the chiller charging connection • Remember that in push/pull, the compressor should never be directly pulling liquid – it should move vapor only, using pressure difference to move the liquid externally

💭 Think About

• First, with 1a and 1b already open, trace the path the liquid refrigerant would take from the chiller shell to the storage tank. Which valves must be open so there is a continuous liquid path, and which must be closed so the liquid does not shortcut back toward the compressor? • Next, trace the vapor circuit: from the storage tank vapor space, through the recovery unit compressor and condenser, and back into the chiller. Which valves must be open for that vapor loop, and which must be closed so the compressor cannot pull from or discharge to the wrong place? • For each answer choice, ask: does this lineup let the compressor handle only vapor, while the separate hose/line carries only liquid by pressure difference? Eliminate any choice where the compressor could ingest liquid or the tank could be vented to atmosphere.

✅ Before You Answer

• Verify which numbered valve is the storage tank vapor/charging valve and which is the liquid/charging valve at the chiller; those two must be connected for the liquid path. • Check that the storage tank vent valve is closed during recovery so refrigerant is not lost to atmosphere. • Confirm that the valves around the recovery unit condenser and water inlet/outlet are positioned so that condenser cooling water can flow, and so that compressor discharge goes through the condenser before returning to the chiller.