What are the pressure test leak detection methods for screw chiller refrigeration systems?

1. Close the discharge valve of the compressor, open all other valves in the system (such as the discharge valve of the liquid reservoir, expansion valve, etc.), unscrew the tapered plug on the discharge valve, and connect the corresponding discharge valve. trachea.

2. After the system is properly adjusted, start the compressor. The preparation before starting the compressor is the same as that of the ammonia compressor.

3. The compressor can be performed intermittently during vacuuming, but the oil pressure of the compressor should be 200 mmHg higher than the suction pressure. If the oil pressure relay is installed, the contacts of the oil pressure relay should be temporarily kept in the normal state, otherwise, the pressure will be lower than the setting value of the oil pressure relay, the compressor will stop automatically, which will affect the vacuuming work.

4. When the pressure is pumped to 650 mmHg, the compressor cannot discharge gas. The taper screw hole of the discharge valve can be blocked by hand, and the discharge valve of the compressor can be quickly fully opened to close the valve shut-off device tightly. Loosen the hand and screw on the tapered screw plug. And stop the operation of the compressor.

5. After the system is vacuumed, let it stand for 24 hours, and the vacuum gauge is qualified if it does not rise more than 5 mmHg.