Leakage inside the fluorine gas valve
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During debugging of a project, it was found that there was internal leakage in the fluorine gas valve. Some people suggested installing a PTFE gasket on the valve core to ensure a tighter seal when the valve is closed. Is that possible? Currently, Su Valve’s bellows globe valves are being used, with the sealing surfaces in direct contact with each other. Are there ones with soft seals?
Replace it with a valve featuring a soft seal; a hard seal is inferior to a soft seal. 412372706
It’s completely misleading; no one knows the actual operating conditions in question. Who says that soft seals are necessarily better than hard seals? It’s pure misinformation! ! ! Hard-sealed valves are precisely widely used in high-temperature or medium-high pressure or hazardous media or low-temperature or... applications ； Soft-sealed valves are generally not used much in such applications. Besides, I’ve never seen a globe valve with a soft seal! ! ! Lack of knowledge :）
The sealing performance is definitely better with soft seals; it also depends on the operating temperature – if the temperature exceeds the limit for PTFE, it won’t work
1. The function of the bellows seal is to prevent external leakage at the valve stem; it has little effect on internal leakage and can be said to be practically useless. Internal leakage still needs to be considered in terms of the valve’s structural design and the sealing pairs. 2. The factors affecting internal leakage include the material of the sealing surfaces, the machining accuracy and surface finish of these surfaces (especially for metal sealing pairs), and the sealing specific pressure. Under other identical conditions, increasing the sealing specific pressure will enhance the sealing capability of the sealing pair. 3. The operating conditions (temperature, pressure) and diameter of the system are unknown; if permitted, a globe-type stop valve with linear sealing can be used, which will provide better sealing performance. If that doesn’t work, consider switching to a valve with better sealing properties.
PTFE is not suitable for high-temperature fluorine gas.
The stop valve is lined with white PTFE. The model is J41F46
The disadvantages are obvious: 1. The operating temperature and pressure are limited； 2. The lining layer tends to wear out easily, especially when used for throttling. 3. External leakage is difficult to resolve.