Correct operation method and precautions of the ho

Correct operation methods and precautions of valves

correct operation methods and precautions of valves: rubber compounds made of soybean oil are actually easier to integrate with other compounds (such as silicon dioxide) that make tires. Valves should not only be able to install and maintain, but also be able to operate

I. opening and closing of manual valve:

1. Manual valve is the most widely used valve. Its handwheel or handle is designed according to ordinary manpower, taking into account the strength of the sealing surface and the necessary closing force. Therefore, you cannot use a long lever or a long wrench to move. Some people are used to using the wrench. They should pay strict attention not to use too much force, otherwise it is easy to damage the sealing surface or break the handwheel and handle

2. When opening and closing the valve, the force should be stable without impact. The components of some high-pressure valves with impact opening and closing have considered this impact force, which is not equal to that of general valves

3. Before opening the steam valve, it should be heated in advance and condensed water should be removed. When opening, it should be as slow as possible to avoid water hammer

4. When the valve is fully opened, the handwheel should be reversed a little to tighten the threads to avoid loosening and damage. For rising stem valves, remember the valve stem position when fully open and fully closed to avoid hitting the top dead center when fully open. And it is convenient to check whether it is normal when it is fully closed. If the valve office falls off, or large debris is embedded between the valve core seals, 2 it is important to show the latest achievements in the key utilization fields of new materials, and the valve stem position will change when it is fully closed

5. When the pipeline is initially used, there is a lot of dirt inside. You can slightly open the valve, flush it away by using the high-speed flow of the medium, and then gently close it (you can't close it quickly or violently to prevent residual impurities from injuring the sealing surface), open it again, repeat this for many times, flush the dirt, and then put it into normal operation

6. If the valve is normally open, there may be dirt on the sealing surface. When it is closed, it should also be washed clean by the above method, and then officially closed

7. If the hand wheel and handle are damaged or lost, they should be equipped immediately, and can not be replaced by a flexible wrench, so as to avoid damaging the four sides of the valve stem, ineffective opening and closing, and resulting in accidents in production

8. Some media are cooled after the valve is closed, causing the valve to shrink. 8. The operator of bio based synthetic materials should close it again at an appropriate time, so that there are no cracks on the sealing surface. Otherwise, the media flows through the cracks at a high speed, which is easy to erode the sealing surface

9. During operation, if it is found that the operation is too laborious, the reason should be analyzed. If the packing is too tight, it can be loosened appropriately. If the valve rod is skewed, personnel should be notified to repair it. When some valves are in the closed state, the closing parts are heated and expanded, causing difficulty in opening; If it must be opened at this time, loosen the bonnet thread by half a turn to one turn to eliminate the valve stem stress, and then turn the handwheel. Inlet pump valve

II. Precautions:

1. High temperature valves above 200 ℃ are installed at normal temperature, but after normal use, the temperature rises, the bolts expand by heating, and the gap increases. Therefore, they must be tightened again, which is called "hot tightening". Operators should pay attention to this work, otherwise it is easy to leak

2. When the weather is cold, the water valve is closed for a long time, and the ponding behind the valve should be removed. After the steam valve stops, the condensate should also be drained. The valve bottom is like a plug, which can be opened for drainage

fixture III 3. Some non-metallic valves are hard and brittle, and some have low strength. During operation, the opening and closing force should not be too large, especially not strong. Also pay attention to prevent objects from bumping

4. When the new valve is used, the packing should not be pressed too tightly to avoid leakage, so as to avoid too much pressure on the valve stem, accelerated wear, and difficult opening and closing