Valve packing life2016-11-15
In the valve design or use experience, the lift valve packing is mostly asbestos packing or graphite packing or polytetrafluoroethylene V-type packing, but these kinds of packing are subject to the number of valve opening and closing restrictions, that is, with the number of valve opening and closing Increase, the filler will wear, the gap gradually increased to a certain number of times (according to statistics will not exceed 2000 times) the valve will leak from the filler. After the leak, you need to re-press the packing gland. This program is suitable for the occasion of the number of valve opening and closing.
If the valve opening and closing frequency is frequent, which will undoubtedly increase the use of the valve, maintenance costs.
Is there any one that can be sealed in the valve after opening 100-200 million times, still able to seal the design? The answer is yes.
One way is to add a gasket below the packing, add a spring under the gasket (spring preload required to calculate), when the filler wear, due to the role of the spring, it will re-compress the packing to seal. This approach is currently through the use of inspection, can only reach 50-100 million times without opening and closing, need to use the annual overhaul, re-tighten the packing gland, can only reduce the usual maintenance.
Another way is to use hydraulic, pneumatic sealing technology, change the original valve design ideas, the use of oil in the filler seal slip ring, increase the 0 ring (need to calculate the friction, sealing pressure, to determine the slip ring and 0 Type of seal). This approach through the use, to achieve the opening and closing of 2 million times without leakage, but 0-type ring to aging, the use of time only 5 years, while higher costs.
If the valve opening and closing frequency is frequent, which will undoubtedly increase the use of the valve, maintenance costs.
Is there any one that can be sealed in the valve after opening 100-200 million times, still able to seal the design? The answer is yes.
One way is to add a gasket below the packing, add a spring under the gasket (spring preload required to calculate), when the filler wear, due to the role of the spring, it will re-compress the packing to seal. This approach is currently through the use of inspection, can only reach 50-100 million times without opening and closing, need to use the annual overhaul, re-tighten the packing gland, can only reduce the usual maintenance.
Another way is to use hydraulic, pneumatic sealing technology, change the original valve design ideas, the use of oil in the filler seal slip ring, increase the 0 ring (need to calculate the friction, sealing pressure, to determine the slip ring and 0 Type of seal). This approach through the use, to achieve the opening and closing of 2 million times without leakage, but 0-type ring to aging, the use of time only 5 years, while higher costs.
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