What is ASTM A795 ERW pipe?

ASTM A795 ERW pipes are electric resistance welded pipes manufactured according to the standards set by ASTM International. These pipes are specifically designed for fire protection systems and meet strict quality and performance criteria.

1. ASTM A795 Standard

This specification applies to black or hot-dipped galvanized welded and seamless steel pipes used in fire protection systems.

Key Details:

Size Range: ASTM A795 covers pipe sizes from NPS (Nominal Pipe Size) 1/2 inch to 10 inches.

Surface Treatment: The pipes can be either uncoated (black) or hot-dip galvanized to provide enhanced corrosion resistance.

Types and Grades: ASTM A795 pipes are classified into types (e.g., Type E) and grades (e.g., Grade B), each with specific performance requirements.

2. ERW Pipe Manufacturing

"ERW" refers to electric resistance welding, a process where the edges of the steel pipe are heated through resistance and fused together to create a welded seam.

3. Characteristics and Applications of ASTM A795 ERW Pipe

(1) Features:

Heat and Pressure Resistance: These pipes are designed to withstand high pressure and temperature, maintaining functionality in extreme conditions.

Corrosion Resistance: Galvanized versions offer protection from corrosion, increasing their durability in moist or chemically harsh environments.

Versatility: ASTM A795 ERW pipes come in various sizes, wall thicknesses, and grades, suitable for diverse applications.

(2) Applications:

ASTM A795 ERW pipes are primarily used in fire protection systems, such as indoor and outdoor fire water supply pipelines, fire hydrants, sprinkler systems, and semi-wet automatic sprinkler systems.

4. Surface Treatments for ASTM A795 ERW Pipe

(1) Hot-Dip Galvanizing:

This process involves immersing the pipe in molten zinc to create a protective coating that guards against corrosion. The general process includes:

Steps: Degreasing → Pickling → Rinsing → Dipping in plating solvent → Drying → Galvanizing → Cooling → Inspection.

(2) Electro-Galvanizing:

Electro-galvanizing is used to apply a thinner, decorative zinc coating to steel objects. This process helps to enhance corrosion resistance, extend the pipe's service life, and improve appearance. Available finishes include blue and white, silver, black, and military green.

(3) Powder Coating:

This involves applying a dry powder to the pipe surface, which is then cured through heat. Black powder-coated pipes are commonly used in various applications.

(4) Painting:

For fire protection applications, ASTM A795 ERW pipes are often painted, typically in red, to ensure visibility and compliance with fire safety standards. The paint provides additional corrosion resistance and makes the pipes easily identifiable, particularly during emergencies.

5. Schedule 40ASTM A795

6. Schedule 10ASTM A795