The black extended internal thread pipe couplings is a high-precision, high-standard long thread pipe fitting product designed to meet the pipeline connection needs of different countries around the world.

1. **Material and production**

- Made of high-quality seamless pipe cutting to ensure that the product has high strength, pressure resistance and durability.

2. **Production process**

- **Cutting**: The seamless pipe is precisely cut and the end face burrs are trimmed to ensure accurate and smooth dimensions.

- **Sandblasting**: The cut pipe fittings are sandblasted to remove surface impurities and rust to provide better adhesion for subsequent thread processing.

- **Thread processing**: Due to the difficulty of processing the internal thread of the product, high-precision equipment and professional technical support are required to ensure the accuracy and consistency of the thread.

3. **Thread standard**

- Supports a variety of international standard threads, including:

- **ISO7/1 (BSP)**: International general pipe thread.

- **ISO228**: Non sealing pipe thread.

- **NPSC**: American standard thread seal pipe thread.

- **DIN2999** and other countries' thread standards.

- Specific thread standards can be customized according to customer needs to meet the diverse needs of the global market.

4. **Product Features**

- **High precision**: High requirements for internal thread processing to ensure tight connection and good sealing.

- **High strength**: Seamless pipe manufacturing, excellent pressure resistance.

- **Corrosion resistance**: Optional stainless steel or alloy steel materials, suitable for corrosive environments.

- **Wide applicability**: Supports multiple thread standards to meet global customer needs.

- **Extended design**: The extended structure facilitates the installation of long pipe fittings and is suitable for complex pipeline systems.

5. **Application scenarios**

- Applicable to special industries such as high pressure and ships, as well as occasions requiring high sealing and high strength.

6. **Specifications and parameters**

- **Specifications**: DN15~DN100 (1/2"~4").

- **Steel pipe**: SCH40, SCH80, SCH160, XS, XXS, etc.

- **Process**: sawing, sandblasting, thread processing, rust prevention, packaging.

7. **Usage**

- Can be directly connected to external threaded pipes, suitable for occasions requiring high-precision thread matching.

- The extended design is easy to install, especially suitable for complex pipeline systems.

**Summary**: The black extended internal thread pipe couplings is a high-precision and difficult pipe fitting product suitable for harsh industrial environments. It supports a variety of international thread standards and is an ideal choice for pipe connection and welding equipment. Its extended design and professional processing technology enable it to perform well in complex pipeline systems and is trusted by customers around the world.