Systems containing more than 110 pounds (49.9 kg) of refrigerant shall have stop valves installed at the following locations:
- The suction inlet of a compressor, compressor unit, or condensing unit.
- The discharge outlet of a compressor, compressor unit, or condensing unit.
- The inlet of a liquid receiver, except for self-contained systems or where the receiver is an integral part of the condenser or condensing unit.
- The outlet of a liquid receiver.
- The inlets and outlets of condensers where more than one condenser is used in parallel in the systems.