Common threaded pipe fittings

Common threaded pipe fittings

There are ordinary threads, cylindrical pipe threads, and tapered pipe threads. Common threads are mostly used for fasteners, such as bolts and nuts, while pipe threads are used for the connection of pipes and fittings. Pipe threads are divided into non-thread sealed pipe threads and threads. Sealed pipe thread.

Thread is divided into transmission thread and transmission thread

The tooth shapes are trapezoidal, rectangular, saw-shaped and triangular.

Used for sealing connection, mainly pipe thread, taper thread and taper pipe thread.

Thread is divided into ordinary thread

The tooth shape is triangular and used to connect or fasten parts. Ordinary threads are divided into coarse and fine threads according to the pitch, and the connection strength of fine threads is higher.

Introduction to thread related knowledge

"Thread" refers to a spiral-shaped continuous convex portion with a specific cross-section made on the surface of a cylinder or cone. Thread is divided into cylindrical thread and conical thread according to the shape of the parent body. According to the position of the parent body, it is divided into external thread and internal thread. According to its cross-sectional shape (teeth), it is divided into triangular thread, rectangular thread, trapezoidal thread, and sawtooth thread. And other special-shaped threads.

Chemical identification method of stainless steel. Sulfuric acid test method

Sulfuric acid immersion stainless steel can distinguish 302 and 304 from 316 and 317. The cut edge of the sample must be finely ground, and then cleaned and passivated in sulfuric acid with a volume concentration of 20%-30% and a temperature of 60-66°C for half an hour. The volume concentration of the sulfuric acid solution is 10% and heated to 71°C. When 302 and 304 are immersed in the solution, the steel is quickly corroded and a lot of bubbles are generated. The sample turns black within a few minutes, while the 316 and 317 steel samples are not corroded or corroded very slowly (no bubbles are generated). The test does not change color within 10-15 minutes. If a sample with known composition is used for simultaneous test for approximate comparison, the test can be more accurate.

www.superbheater.com