Seeking advice on instrument material specifications

ib is the same as lb. Φ14 and M14 are not the same. The symbol Φ represents the diameter; Φ14 means a diameter of 14 mm (usually, this refers to the outer diameter unless otherwise specified) ； In M14, the “M” denotes a regular thread, while the number 14 indicates the large diameter of the thread. Characteristic codes, uses, and descriptions: Regular thread – Coarse thread. M is the most commonly used type of connection thread. When the diameters are the same, the pitch of a fine thread is smaller than that of a coarse thread; the pitch for coarse threads is not specified. Fine thread – M. Pipe thread: G is a commonly used thread for pipe connections, with a small pitch and thread profile. Its size code is given in inches and is approximately equal to the diameter of the pipe’s bore. The major diameter of the thread should be determined from relevant standards. The code R denotes external tapered threads, Rc denotes internal tapered threads, and Rp denotes internal cylindrical threads. 55° sealing pipe threads and Rc sealing threads can maintain a seal between the inside and outside of the pipeline connection under certain pressures. Tr refers to two commonly used transmission threads used for transmitting motion and power; trapezoidal threads can transmit power in both directions, while serrated threads are used for transmitting power in one direction. Serrated threads: B – Suitable for M20*1.5 instrument connectors; model number: ptfe-gc-18-8-2. In this model number, PTFE is an abbreviation; the Chinese name for PTFE is polytetrafluoroethylene, and its other names include PTFE, Teflon, Teflon, Teflon, F4, and “the king of plastics”. The English name is Polytetrafluoroethylene, abbreviated as Teflon ； In 18-8-2, 18 represents the outer diameter of the gasket, 8 represents its inner diameter, and 2 represents its thickness. If you have any questions, we can discuss them on QQ251607134

1. ib and lb: There is no requirement for ib; it is suspected to be a typo. lb stands for pound, and it is the abbreviation for the pressure unit pound in the American system; for example, 150lb = PN2.0MPa, 300lb = PN5.0MPa, 600lb = PN11.0MPa, 900lb = PN15.0MPa, 1500lb = PN26.0MPa. Using just “lb” these days is not very precise; it should be written as Class150, Class300..., which is the correct way to denote pressure grades according to ASME standards. 150lb was the notation used under the previous ANSI standards; those standards are no longer in use, as ANSI has been merged into ASME, and the notation specified by ASME should be used instead. But since many people are already accustomed to the ANSI notation, it’s sufficient to understand the relationship between them; there’s no need to go into too much detail. 2. PE is an abbreviation for PIPE END; it refers to the pipe opening or groove, and this requirement exists to facilitate welding on site. Grooves must be created before welding during cladding processes. The correct notation is: 1/2NPT-PEΦ14. This is a fitting; one end has a 1/2NPT thread, while the other end consists of a short tube with a Φ14mm diameter, and the tube end is beveled. 1/2NPT-PEΦ14, with a slip connection between the two ends for easy disassembly. The other points mentioned on the second floor are great.

IB is a type of intrinsically safe signal, with a circuit current limit of 150 mA; IA is 100 mA. LB is an unofficial American unit of pressure. It has been well explained by others upstairs.

IB is the explosion protection rating; for example, IA denotes intrinsically safe