Generally, the connection methods of pipes and fittings include threaded connection, grooved connection, flange connection, welding and socket connection.

Below 2-1 / 2 “, threaded connection is often used, and more than 2” has been grooved connection, socket connection and welding. Flange connection is mainly used to connect valves, etc.

For black pipe fittings, pay attention to the following problems when connecting.

1. The pipe size is consistent with the pipe fitting size. If the description of pipe size is different in different countries, it is necessary to communicate with the supplier in detail.

2. Different types of pipe fittings are selected in different application fields. Galvanized surface treatment is usually adopted in the field of fire protection. Black pipe fittings are usually used in natural gas and oil fields

3. Whether the working pressure matches. Generally, the working pressure of black pipe fittings is 2.5MPa, 25bar and 360psi The supplier is required to provide corresponding working pressure test report, or third-party test report, or corresponding certification documents.

4. Requirements for threads. Threads are divided into BSPT, BSPP, NPT and iso-228. This is very important. The wrong selection of threads will seriously affect the sealing effect of the pipeline. Plug gauge and ring gauge can be used to test whether the thread is correct.

5. Standard installation length. For the connection between pipes and pipe fittings, the length of screw in shall not be too short or too long. Too short will affect the firm connection and sealing effect. Too long connection will damage the pipe wall of pipe fittings and affect the service life of pipe fittings.

6. Service life of pipe fittings: the pipe fittings usually need to be used for many years after connection. Once damaged, it is relatively difficult to repair, and it will cause dangerous situations and losses such as water leakage and air leakage. Therefore, the service life of black pipe fittings is required to be at least 10 years, and it is best if it can reach more than 25 years.

7. Selecting high-quality pipe fittings can greatly shorten the installation time and reduce the installation cost.

If you have any questions about the connection of black pipe fittings, please contact Jianzhi casting group, and we will provide you with professional answers and services.