4.2 The hydrogen content in the chlorine main pipe is ≤0.4%. The hydrogen content in tail gas after chlorine liquefaction should be ≤4.0%.

4.3 The pressure of filling liquid chlorine should not exceed 65438±0.65438±0 MPa.

4.4 The filling amount of liquid chlorine in liquid chlorine storage tanks, metering tanks and gasifiers should not be greater than 80% of the container volume. After liquid chlorine filling, measures should be taken to prevent the pipeline from being closed by liquid.

4.5 The liquid chlorine in the liquid chlorine evaporator should not be charged into the liquid chlorine cylinder.

4.6 Liquid chlorine vaporizer, precooler, heat exchanger and other equipment should be equipped with sewage discharge (NCl3) device and sewage treatment facilities, and the NCl3 content should be analyzed regularly, and the NCl3 content in sewage should not be greater than 60 g/L, otherwise, the frequency and quantity of sewage discharge should be increased, and monitoring should be strengthened.

4.7 In order to prevent the chlorine compressor or Nessler's pump from being cut off, resulting in chlorine overflow from the electrolyzer, one of the following measures should be taken:

A) The chlorine production system is equipped with a chlorine absorption device to prevent chlorine from overflowing;

B) equipped with chlorine compressor, Nessler's pump outlet chlorine interlock valve or check valve;

C) Equipped with electrolytic DC power supply, chlorine compressor, outlet valve of Nessler's pump, starting power supply of chlorine absorption device and other devices, and interlocked with the power supply of chlorine compressor and Nessler's pump.

4.8 Chlorine equipment, pipelines and valves should be cleaned, purged and dried before installation, and the reaction products stranded in the reaction equipment and pipelines should be removed regularly to eliminate blockage. Valves should be pressure tested one by one, and a regular replacement system should be established for important pipelines and valves.