Must know! Safe operation of refrigeration valves
The switching operation of various valves is the main task in the operation of the refrigeration system. The function of the valve is to control and guide the flow and direction of the 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 follow the operating procedures to avoid accidents. According to their use, cold storage valves mainly include stop valves, expansion valves and safety valves. There are two types of globe valves: straight-through valve and angle valve. The safe operation of the valve should do the following:
1) The operator must be aware of the target for the operation of the valve, and do not open other valves by mistake and cause human accidents.
2) When opening the suction valve of the compressor, the discharge valve of the condenser or the liquid reservoir, it must be done slowly, and sometimes it should be turned on and off alternately to avoid the wet stroke accident of the compressor due to the excessively fast opening speed.
3) During the opening of each valve, especially when it is close to the maximum opening, the handwheel must be moved slowly and not too much force to avoid the valve core being stuck by the valve body and the valve plate falling off. When the valve is at the maximum opening (as long as the handwheel cannot be moved), the handwheel should be rotated one or two times.
4)During the closing process of each valve, the operator should pay attention to the appropriate force and not excessive force, so as not to damage the valve.
5) For pipelines and equipment with liquid refrigerant, it is strictly forbidden to close the valves at both ends at the same time, so as to avoid absorbing external heat and causing the liquid to produce volume de-expansion and cause the pipeline or equipment to burst and leak ammonia. Under normal circumstances, most liquid bursts burst at the valve. The correct way to prevent liquid explosion is to first evacuate the liquid in the tube when 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, and the valve connecting the other end with the equipment should be in an 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 before closing 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 include: the liquid pipeline between the condenser and the liquid reservoir, the pipeline between the high-pressure liquid reservoir and the expansion valve, the liquid pipeline with shut-off valves at both ends, the level gauge of the high-pressure equipment, the liquid between the ammonia container Balance pipes, liquid distribution stations, pipes below the outlet valve of the circulating liquid reservoir to the ammonia double suction end, the liquid supply pipe of the ammonia pump, the pipes between the liquid reservoir and the emergency ammonia discharge device, and all pipes that may cause liquid explosion.
6) For valves that have not been opened and closed for a long time, the opening and closing flexibility should be checked regularly.
7) The safety valve in the refrigeration system must be calibrated once a year, and the safety valve in question should be repaired or replaced in time.
8) The red and yellow opening and closing signs made of color steel plates are added to the hand wheel of the valve to avoid misoperation as much as possible.
