Internal thread gate valve
Thread Content
Why is such a high temperature used for the internal threaded gate valve in the attachment? Shouldn’t flange connections be used at high temperatures? Is there a thread sealant with such high temperatures? I would appreciate some guidance from experts, thank you!
Valves with internal threads are hardly used in the petrochemical industry; there are also sealing gels that can withstand temperatures of up to 800°C.
The image above is taken from Part 3 of Zhang Dejiang’s fifth edition of the Manual on Process Piping Design for Petrochemical Plants. Does this mean that internal thread valves are still used in the petrochemical industry? Please advise
The connection sealing for internal thread valves is not done using sealant. Depending on the type of sealing surface, gaskets are used. Such as copper gaskets, aluminum gaskets, PTFE gaskets, etc. It is commonly used on instruments.
This temperature refers to the ability of the valve material to withstand 425°C, not the temperature of the threads； Threads are prone to leakage at high temperatures, but they can still be used
It is rarely used; the sealing of valves with internal threads does not rely on the threads themselves, but rather on elements such as lens gaskets for sealing.
For such high-temperature applications, it’s better to use fewer threads, as this reduces the risk of leaks
Since the diameter is relatively small (it’s probably DN15), a threaded connection was used. According to current design concepts, such choices are now very rare.
Small-diameter high-temperature gate valves can have threaded connections. Based on the materials provided, the maximum operating temperature for these materials is 425°C; as long as the material used for the gate valve is suitable for high temperatures, that will suffice. Only in cases where the operating conditions involve high temperatures and pressures would a different type of connection be required.
Is high-temperature threaded connection requires gaskets? It’s not using sealant, is it? Please give me some advice. Thank you!
It’s usually a sealant! I’ve never seen it in any other way!