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Safe Operation Of Refrigeration Valves

Apr 07, 2020

Safe operation of refrigeration valves

The switching operation of various valves is the main work in the operation of the refrigeration system. The role of the valve is to control and guide the flow and direction of refrigerant in the system, cut off and conduct the connection between the equipment and the equipment or the equipment and the outside world. Improper operation of the valve can cause unsafe factors or cause accidents, so the operation of the valve must strictly abide by the operating rules to avoid accidents. Cold storage valves mainly include globe valves, expansion valves and safety valves according to their uses. There are two types of globe valves: straight-through valves and angle valves. The safe operation of the valve should do the following work:

1. The operator must be sure about the operation of the valve, and do not accidentally open other valves to cause human accidents.

2. When opening the suction valve of the compressor, the discharge valve of the condenser or the accumulator, it must be carried out slowly, and sometimes it should be started and stopped alternately to avoid the wet stroke accident of the compressor due to the excessively fast opening speed.

3. During the opening process of each valve, especially when it is close to the maximum opening, be sure to slowly pull the handwheel, and do not use excessive force, so as to avoid the phenomenon that the valve core is caught by the valve body and the valve is pulled off. When the valve is at the maximum opening (limited to the handwheel can not move), the handwheel should be rotated one or two times.

4. The operator should pay attention to the proper force during the closing of each valve, and not use too much force, so as not to damage the valve.

Must know! Safe operation of refrigeration valves

5.For pipes and equipment with liquid refrigerant, it is strictly forbidden to close the valves at both ends at the same time, so as to avoid the expansion of the liquid due to the absorption of external heat and the expansion of the liquid, which will lead to the accident of ammonia leakage in the pipe or equipment. Under normal circumstances, most liquid bursts crack at the valve. The correct way to prevent liquid explosion is to evacuate the liquid in the tube before closing the liquid tube valve. Under special circumstances, when the liquid pipe cannot be evacuated, only the valve at one end of the liquid pipe should be closed, so that the valve connected to the equipment at the other end is in the open state. If the compressor is completely stopped, the supply of the liquid reservoir should be closed first. Liquid valve, wait for the system and liquid pipe to be evacuated, and then close the main liquid supply valve to the regulating station.

In the refrigeration system, special attention should be paid to the parts where liquid explosion may occur. These parts are: the liquid pipeline between the condenser and the reservoir, the pipeline from the high-pressure reservoir to the expansion valve, the liquid pipeline with shut-off valves at both ends, the liquid level gauge of the high-pressure equipment, and the liquid between the ammonia container Balance pipe, liquid distribution station, the pipeline below the outlet valve of the circulation reservoir to the double suction end of ammonia, the liquid supply pipeline of the ammonia pump, the pipeline from the reservoir to the emergency ammonia drain, and all pipelines that may cause liquid explosion.

Must know! Safe operation of refrigeration valves

6. Valves that do not open and close for a long time should be regularly checked for opening and closing flexibility.

7. The safety valve in the refrigeration system must be calibrated once a year, and the safety net in question should be repaired or replaced in time.

8. Attach the red and yellow opening and closing plates made of colored steel plates to the handwheel of the valve to avoid misoperation as much as possible.