G-thread sealing issues
Thread Content
There are some connectors on pneumatic actuators, such as those for pressure relief valves, which use G-thread connections. How is sealing achieved in such cases? Is it still appropriate to use gaskets, and how should they be installed?
In the mechanical design handbook, pipe threads are divided into those without thread sealing and those with thread sealing. The 55° type without thread sealing is indicated, for example, as G 1-1/2A (1 and 1/2; I’m not sure how to write that). Therefore, you should be using a type without thread sealing, and gaskets are required in such cases. For more details, refer to Volume 2 of the mechanical design handbook, sections 1.8, 1.9, and 1.10
What’s the point of thread sealing anyway? For tapered threads, how many of them are sealed through clearance fit? Things like HVAC pipes – for tapered threads, sealing is achieved by wrapping hemp fiber or tape around them. The function of threads, I think, is to connect and attach things while withstanding pressure. {:2_45:}
For high pressure, use gaskets for cross-sectional sealing; for low pressure, Teflon tape is sufficient. Generally, we use Teflon tape for pressures below 16 kilograms