Connect the vacuum pump to the compound pressure gauge; open the compound pressure gauge and vacuum pump to vacuum the indoor unit and connecting pipe.

将真空泵连于复合压力表，打开复合压力表和真空泵对室内机和连接管抽真空。

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Circulating water pump inlet pipe and outlet pipe should also install pressure gauge.

循环水泵的进水管和出水管上也应装压力表。

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Metallurgical oxygen system pipe system, should use strict degreasing treatment, needle valve flange J29 Angle Pressure Gauge valve connection.

冶金系统中的氧气管路系统中，宜选用经过严格脱脂处理，法兰连接的针型阀。

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