Notes I took on NPT, PT, G threads, as well as British, American, and metric threads
Thread Content
1: The common pipe threads mainly include the following types: NPT, PT, G, etc. 1) NPT is a 60-degree pipe thread according to American standards, used in North America. 2) PT (known as ZG in China) is a 55-degree sealed tapered pipe thread that belongs to the Whitworth thread family; it is widely used in Europe and the Commonwealth**, especially in the water and gas piping industries. Its taper ratio is 1:16. 3) G is a 55-degree unthreaded sealing pipe thread, belonging to the Whitworth thread family. II: What are the differences between R, Rc, Rp, and G for pipe threads? 1) The term \"R thread\" is a general designation that includes Rc, Rp, R1, and R2. 2) Rc refers to imperial sealed pipe threads, tapered threads, and internal threads (threaded holes). 3) Rp refers to imperial sealed pipe threads, cylindrical threads, and internal threads (threaded holes). 4) G is a British imperial unsealed pipe thread, a cylindrical thread, which can be either an external thread or an internal thread. 5) R1 is the characteristic code for a tapered external thread that mates with a cylindrical internal thread. 6) R2 is the characteristic code for a tapered external thread that mates with a tapered internal thread. III: Differences between metric threads and imperial threads: 1) Metric threads are expressed in terms of pitch, while imperial threads are expressed in terms of the number of threads per inch ； 2) Metric threads have an equilateral profile at 60 degrees, British threads have an isosceles profile at 55 degrees, while American threads have an isosceles profile at 60 degrees ； 3) Metric threads use metric units (such as mm), while imperial and British threads use imperial units (such as inches) ； 4) Those in the industry usually refer to thread sizes in \"minutes\"; one inch equals 8 minutes, 1/4 inch equals 2 minutes, and so on. 5) Additionally: ISO—metric thread standard 60 degrees ； UN—Unified thread standard 60 degrees ； API—American Petroleum Pipe Thread Standard 60 degrees ； W—British Whitworth thread standard 55 degrees.
Thank you to the original poster; I’ve absorbed it quietly.
Thank you. I replaced the pressure gauge, and it wouldn’t tighten no matter what – only then did I realize it had imperial tapered threads while I bought pipes with national standard threaded connections :@:@:@
This manual lists the specifications for various common metric and imperial threads. Link: https://pan.baidu.com/s/1rcm67jNtQT142mNAxnpHUQ To obtain the extraction code, follow the WeChat official account UMCS and reply with “Password 01”.
Little knowledge is still very important.....
Thank you for the summary and sharing! ! ! ! ! ! ! ! ! ! ! ! ! ! !
In applications where explosion protection is required, is it correct to connect the area around the flexible tube at the cable outlet of the explosion-proof junction box to the cable conduit using G threads? Isn’t the G thread a non-sealing type?