Let’s discuss R threads and G threads together
Thread Content
This post was last edited by Wang Tianze on 2017-2-23 at 22:38. Pipe threads are threads located on the pipe wall for connection; there are 55-degree non-sealing pipe threads and 55-degree sealing pipe threads. It is mainly used for connecting pipes, ensuring a tight fit between their internal and external threads, and is available in straight and tapered types. II. The common pipe threads mainly include the following types: NPT, PT, G, etc. (1) NPT is the abbreviation for National (American) Pipe Thread; it refers to the 60-degree tapered pipe thread standard used in North America. For the national standard, refer to GB/T12716-1991. (2) PT (BSPT) is an abbreviation for Pipe Thread; it refers to a sealing tapered pipe thread with a 55-degree angle, and it belongs to the Whitworth thread family. It is widely used in Europe and the Commonwealth countries**, especially in the water and gas piping industries. The taper ratio is 1:16, and the relevant national standard can be found in GB/T7306-2000. It is called ZG in China. (3) G is a 55-degree unsealed pipe thread, belonging to the Whitworth thread family. Marked as G represents cylindrical threads. Refer to GB/T7307-2001 for national standards. III. Several principles for distinguishing thread types based on size codes: 1. G denotes 55-degree non-sealing cylindrical internal threads ； 2.Rp represents the internal thread of a 55-degree sealed cylinder ； 3. Rc denotes a 55-degree sealed tapered internal thread with a taper ratio of 1:16 ； 4. R denotes a 55-degree sealed tapered external thread with a taper of 1:16 ； R1 pairs with Rp, while R2 pairs with Rc. 5.NPSC represents a 60-degree sealed cylindrical internal thread ； 6.NPT stands for 60-degree sealed tapered thread (internal/external) ； So the question arises: for the threaded types of galvanized wire conduit that we commonly use, are they G threads or R threads? What type of thread is used for union fittings? 2. Can G threads and R threads be connected to each other? Does using sealing tape also provide a sealing effect? Let’s discuss it; those who have used it in practice, please share!
The threads commonly used in the processing of galvanized pipes are G threads; if the quality of these threads is good, an sealing tape can serve to provide a seal. For example, instrument air pipelines, heating pipelines, and domestic water pipelines all use G threads.
But I notice that the external threads of the galvanized air supply pipes we use all have a taper – shouldn’t G threads be straight-threaded pipes instead?
But I notice that the external threads of the galvanized air supply pipes we use all have a taper – shouldn’t G threads be straight-threaded pipes instead?
1. The common thread types for pipelines are G and R; the internal thread of union fittings is of type G. 2. Using tape on R and G threads allows them to be used interchangeably, and this is exactly how we do it in the field
I only know that the ring gauges and plug gauges for ANPT purchased in China are not very reliable in terms of quality; it’s easier with others – as long as the specifications are provided, there’s no problem with the threads.
This post was last edited by cubel on 2017-2-20 at 20:23. I only know that the ring gauges and plug gauges for ANPT purchased in China are not of high quality; it’s easier to find ones that meet the specified requirements, as threading isn’t an issue in such cases. Ugh, how did it get sent twice?……
The forum started to change yesterday, which caused delays; I noticed that as well
For posts that have been sent, when one clicks to post a reply, it no longer appears quickly, giving the illusion that it’s not possible to post replies. Please ask the administrator to fix this issue
We always wrap tape around galvanized pipes!