Points worthy of notice on forged steel valve operation-part two
Some media tend to cool after the forged valve is closed, so that the valve parts are shortened. Therefore, the operator should close the forged valve again at the right time, so that there is no gap left on the sealing surface, otherwise, the medium will flow through the gap at a high speed and simply erode the sealing surface.
During the forged valve operating, if you find that the operation is too laborious, you should analyze the reason. If the packing is too tight, it can be properly relaxed. If the stem is tilted, it should be reported for the repair by professional workers. As for some forged valves, in the closed condition, the sealing elements expand when heated; as a result, it is difficult to open. If there is any need to open at this moment, the bonnet thread should be loosened half a turn to one turn, the stem stress is eliminated, and then we can pull the hand wheel for opening.
(2) Notes
1. For the high temperature valve above 200 °C, with the increase of the temperature, the bolt expands when heated and the gap enlarged, after normal running, because the forged valve is installed normal temperature. So it is necessary to tighten again, which is called “thermal fastening”, the operator should pay attention to this operation, or else, the leakage will occur.
2. When the weather is cold, the water forged valve is closed for a long time. In this case, the water behind the forged valve should be removed. For the forged steam valve, the condensate water should also be removed after steaming stops. If the bottom of the forged valve is blocked, it should be turned over to drain.
3. Among non-metallic valves, some are hard and brittle, and some are of low strength. During operating, the opening and closing force should not be too large, especially not to make it violently. Also, we should prevent the objects from collision.
4. When a new forged valve is used, the packing should not be pressed too tightly, only to the extent there is no leak instead, to prevent the stem from being pressed too much and accelerated wearing, and in case that the opening and closing is laborious.
During the forged valve operating, if you find that the operation is too laborious, you should analyze the reason. If the packing is too tight, it can be properly relaxed. If the stem is tilted, it should be reported for the repair by professional workers. As for some forged valves, in the closed condition, the sealing elements expand when heated; as a result, it is difficult to open. If there is any need to open at this moment, the bonnet thread should be loosened half a turn to one turn, the stem stress is eliminated, and then we can pull the hand wheel for opening.
(2) Notes
1. For the high temperature valve above 200 °C, with the increase of the temperature, the bolt expands when heated and the gap enlarged, after normal running, because the forged valve is installed normal temperature. So it is necessary to tighten again, which is called “thermal fastening”, the operator should pay attention to this operation, or else, the leakage will occur.
2. When the weather is cold, the water forged valve is closed for a long time. In this case, the water behind the forged valve should be removed. For the forged steam valve, the condensate water should also be removed after steaming stops. If the bottom of the forged valve is blocked, it should be turned over to drain.
3. Among non-metallic valves, some are hard and brittle, and some are of low strength. During operating, the opening and closing force should not be too large, especially not to make it violently. Also, we should prevent the objects from collision.
4. When a new forged valve is used, the packing should not be pressed too tightly, only to the extent there is no leak instead, to prevent the stem from being pressed too much and accelerated wearing, and in case that the opening and closing is laborious.
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