National standard fire-fighting plastic-coated straight seam steel pipe is a pipe material designed for fire protection systems. It has the characteristics of corrosion resistance, high-pressure resistance, and wear resistance. It is widely used in fire water supply, sprinkler systems, and other fields. The following are its main features and relevant standards:

First, the main features of plastic-coated straight seam steel pipe
1. Strong corrosion resistance: The inner and outer walls of the steel pipe are coated with a plastic layer (such as epoxy resin or polyethylene) to effectively prevent corrosion and extend the service life.
2. High-pressure resistance: The straight seam steel pipe has high mechanical strength and can withstand the high pressure requirements of the fire protection system.
3. Wear resistance: The plastic coating layer reduces the wear of the fluid on the pipe wall and is suitable for long-term use.
4. Smooth inner wall: The inner wall is smooth after plastic coating, which reduces fluid resistance and improves transportation efficiency.
5. Convenient installation: Light weight, various connection methods (such as threads, flanges, grooves, etc.), easy to install and maintain.

Second, the application field of plastic-coated straight seam steel pipe
- Fire water supply system
- Automatic sprinkler system
- Fire gas delivery system
- Other occasions that require corrosion resistance and high-pressure resistance

Third, the relevant standards of plastic-coated straight seam steel pipe
The production and use of plastic-coated straight seam steel pipe for national standard fire protection must comply with the following standards:
- GB/T 5135.20-2010: Automatic sprinkler fire extinguishing system coated steel pipe
- GB/T 17219-1998: Safety evaluation standard for drinking water distribution equipment and protective materials
- GB/T 3091-2015: Welded steel pipe for low-pressure fluid transportation
- CJ/T 120-2016: Plastic-coated composite steel pipe for water supply

Fourth, the production process of plastic-coated straight seam steel pipe
1. Steel pipe preparation: Select high-quality carbon steel and make steel pipes through a straight seam welding process.
2. Surface treatment: Sandblast or pickle the steel pipe to remove rust and impurities.
3. Plastic coating: Use electrostatic spraying or dipping process to evenly coat the inner and outer walls of the steel pipe with a plastic layer.
4. Curing: Ensure that the coating is firmly attached through high-temperature curing.
5. Quality inspection: Perform multiple tests such as appearance, thickness, adhesion, and pressure resistance to ensure compliance with standards.

Fifth, precautions for plastic-coated straight seam steel pipes
- Storage and transportation: Avoid violent collisions and direct sunlight to prevent damage to the coating.
- Installation: Operate according to specifications to avoid damage to the plastic coating layer and ensure the sealing of the system.
- Maintenance: Check regularly and repair damaged parts in time to ensure the normal operation of the system.

Summary
National standard plastic-coated straight seam steel pipes for fire protection are indispensable materials in fire protection systems due to their excellent performance and wide application. Selecting products that meet national standards and properly installing and maintaining them can effectively ensure the reliability of fire protection systems.