What are the types of instrument process connections? What are the types of electrical interfaces?

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We know that when selecting instruments, it is necessary to specify the process connections and electrical connections, such as flanges, threads, and welding. There are lists of common connection types for various types of instruments (temperature, transmitters, flow meters, valves). What other common electrical connections exist besides 1/2\" NPT? Types: straight through fittings, through fittings, tees, elbows, fittings with adjustable nuts, articulated fittings, plugs, transition fittings, etc. Composition of the dual-card socket joint: front clamping ring, rear clamping ring, nut. The commonly used materials are stainless steel and copper. Metric, imperial, and British thread standards. NPT, PT, and G are all pipe threads. NPT is the abbreviation for National (American) Pipe Thread; it represents a 60-degree tapered pipe thread standard used in North America. **The relevant standard can be found in GB/T12716-1991. PT is the abbreviation for Pipe Thread; it refers to a 55-degree sealed tapered pipe thread that belongs to the Whitworth thread family. It is widely used in Europe and the Commonwealth countries. It is commonly employed in the water and gas piping industries, with a taper ratio of 1:16. The relevant standard can be found in GB/T7306-2000. G represents a 55-degree unthreaded sealed pipe thread, also part of the Whitworth thread family; the designation “G” indicates a cylindrical thread. The corresponding standard is GB/T7307-2001. Additionally, the 1/4, 1/2, 1/8 markings on the thread refer to the diameter of the thread size, measured in inches. Those in the industry usually refer to thread sizes in fractions; one inch equals 8 fractions, 1/4 inch is 2 fractions, and so on. G seems to be the general term for pipe threads (Guan); the classifications of 55 and 60 degrees are based on functional considerations, and they are commonly referred to as pipe circles. That is, the thread is formed by machining a cylindrical surface. ZG is commonly known as a tube cone, meaning that the thread is formed by a conical surface; most ordinary pipe fittings are of this type, and they are designated as Rc according to the old national standards. 　　 Metric threads are indicated by pitch, while imperial and British threads are indicated by the number of threads per inch; this is their biggest difference. Metric threads have an equilateral thread profile at 60 degrees, British threads have an isosceles thread profile at 55 degrees, and American threads also have a 60-degree profile. Metric threads use metric units, while imperial and American threads use imperial units. 　　 Pipe threads are primarily used for connecting pipes; their internal and external threads fit tightly together, and there are two types: straight pipes and tapered pipes. The nominal diameter refers to the diameter of the pipe being connected; obviously, the major diameter of the thread is larger than the nominal diameter. 1/4, 1/2, 1/8 are the nominal diameters of imperial threads, measured in inches.