Red plastic-coated fire fighting steel pipe is a steel pipe specially used in fire protection system. It has the characteristics of corrosion resistance, high temperature resistance and easy identification. It is widely used in automatic sprinkler fire extinguishing system, fire hydrant system, etc. The following is a detailed introduction:

Production process of red plastic-coated fire steel pipe
Raw material preparation
Select high-quality carbon steel or alloy steel, such as Q235 or ASTM A53 steel pipe.
Cut the steel pipe to the specified length according to production requirements.
Surface treatment
Degreasing: Remove oil and impurities on the surface of the steel pipe.
Rust removal: Remove oxide scale and rust by mechanical sandblasting or chemical pickling to achieve the specified surface cleanliness (usually Sa2.5 level).
Phosphating or passivation: Enhance the coating adhesion on the surface of the steel pipe and improve the corrosion resistance.
Plastic coating treatment
Preheating steel pipe: Heat the steel pipe to a certain temperature (usually 180℃-220℃).
Inside and outside spraying: Use epoxy resin powder or polyethylene material to evenly coat the inner and outer walls of the steel pipe.
Curing: Send the coated steel pipe into a high-temperature oven (180℃-240℃) to cure the coating to form a dense protective film.
Testing and inspection
Coating thickness detection: Ensure that the standard requirements are met (generally 0.2mm-0.5mm).
Adhesion test: Check whether the coating is firmly attached.
Corrosion resistance test: Simulate damp heat, salt spray and other environmental tests to test the coating performance.
Packaging and storage
Protective packaging of plastic-coated pipes to prevent damage during transportation.

Material and steel grade
The main material of Red plastic-coated fire fighting steel pipe is usually carbon steel or alloy steel. The specific steel grades may include:
Carbon steel material: Q235, Q195 (Chinese standard); ASTM A53 Gr.B, ASTM A106 Gr.B (American standard).
Alloy steel material: Low alloy steel such as 20Mn2, 15CrMo, 12Cr1MoV, etc., are usually used in occasions with higher performance requirements.
The choice of steel grade mainly depends on the design requirements of the fire protection system and the standards of the project location.

Implementation standards
The production of red plastic-coated fire hoses must comply with relevant national or international standards, including:
Chinese standards
GB/T 3091 “Welded steel pipes for low-pressure fluid transportation”
GB/T 5135.11 “Specifications for steel pipes for automatic sprinkler systems”
International standards
ASTM A135/A795 (American standard for fire-fighting steel pipes)
BS 1387 (British standard for galvanized or coated steel pipes)
Industry specifications
NFPA 13 (National Fire Protection Association standard for the installation of automatic sprinkler systems)

The following is a detailed list of the outer diameter, diameter, wall thickness, and length range of red plastic-coated fire-fighting steel pipes in different national standards:
1. Chinese standards (GB/T 3091, GB/T 5135.11)
Outer diameter range: 21.3 mm – 323.9 mm
Nominal diameter (DN): DN15 – DN300
Wall thickness range: 2.0 mm – 8.0 mm
Length range: 6 m, 9 m, 12 m, or customized length as required
2. American Standard (ASTM A135, ASTM A795)
Outer diameter range: 21.3 mm – 323.9 mm
Nominal diameter (NPS): NPS 1/2 – NPS 12
Wall thickness range: 2.11 mm – 8.18 mm (Schedule 10, Schedule 40, Schedule 80)
Length range: 18 ft, 21 ft, 24 ft, or customized length as required
3. British Standard (BS 1387)
Outer diameter range: 21.2 mm – 323.9 mm
Nominal diameter (DN): DN15 – DN300
Wall thickness range: 2.65 mm – 4.85 mm (light, medium, heavy)
Length range: usually 6 m, or customized length as required
4. European Standard (EN 10255, EN 10217)
Outer diameter range: 21.3 mm – 355.6 mm
Nominal diameter (DN): DN15 – DN350
Wall thickness range: 2.0 mm – 10.0 mm
Length range: 6 m, 12 m, or as required
5. Japanese Standard (JIS G3452, JIS G3445)
Outer diameter range: 21.7 mm – 318.5 mm
Nominal diameter (A): 15A – 300A
Wall thickness range: 2.3 mm – 6.5 mm
Length range: 4 m, 5.5 m, 6 m, or as required
6. International Fire Protection Association Standard (NFPA 13, reference ASTM A135/A795)
Outer diameter range: 21.3 mm – 323.9 mm
Nominal diameter (NPS): NPS 1/2 – NPS 12
Wall thickness range: 2.11 mm – 8.18 mm
Length range: 18 ft, 21 ft, 24 ft, or according to project requirements

Features of red plastic coated fire-fighting steel pipe
Excellent corrosion resistance: The coating blocks air, moisture and corrosive substances from contacting the surface of the steel pipe.
High strength and toughness: The steel pipe body has high strength, the coating has good toughness and is not easy to fall off.
Low flow resistance: The inner wall is smooth, reducing water flow resistance and improving transportation efficiency.
Long service life: Suitable for harsh environments, the durability can reach more than 50 years.
Environmental protection: The coating material is non-toxic and pollution-free, meeting fire protection and environmental protection requirements.