ASTM A106 is a specification for seamless carbon steel pipe, primarily used in high-temperature service. It is commonly used in industrial applications where high heat, pressure, and high-stress environments are involved. Below are the key aspects of the ASTM A106 specification:

1. Grades:

ASTM A106 covers three grades of seamless pipe:

Grade A

Grade B

Grade C

2. Chemical Composition:

The chemical composition varies slightly between the grades, especially in terms of carbon content:

Grade A:

Carbon (C): Max 0.25%

Manganese (Mn): 0.27-0.93%

Phosphorus (P): Max 0.035%

Sulfur (S): Max 0.035%

Silicon (Si): Min 0.10%

Grade B:

Carbon (C): Max 0.30%

Manganese (Mn): 0.29-1.06%

Phosphorus (P): Max 0.035%

Sulfur (S): Max 0.035%

Silicon (Si): Min 0.10%

Grade C:

Carbon (C): Max 0.35%

Manganese (Mn): 0.29-1.06%

Phosphorus (P): Max 0.035%

Sulfur (S): Max 0.035%

Silicon (Si): Min 0.10%

3. Mechanical Properties:

Grade A:

Tensile Strength: 48,000 psi (330 MPa) minimum

Yield Strength: 30,000 psi (205 MPa) minimum

Grade B:

Tensile Strength: 60,000 psi (415 MPa) minimum

Yield Strength: 35,000 psi (240 MPa) minimum

Grade C:

Tensile Strength: 70,000 psi (485 MPa) minimum

Yield Strength: 40,000 psi (275 MPa) minimum

4. Manufacturing Process:

Pipes under ASTM A106 are manufactured using seamless processes. This means that the pipes are made without any welded joints, ensuring they are robust and capable of withstanding high-pressure and high-temperature conditions.

5. Application:

ASTM A106 pipes are typically used in refineries, power plants, petrochemical industries, boilers, and pressure vessels. They are suited for carrying fluids like oil, gas, and water at high temperatures and pressures.

6. Testing Requirements:

Hydrostatic Test: Each length of pipe is subjected to a hydrostatic test.

Nondestructive Electric Test: As an alternative to the hydrostatic test, a nondestructive electric test can be performed.

Bend Test: For pipes NPS 2 and under, bend tests are required.

Flattening Test: For pipes NPS 2 and larger, a flattening test is required.

Tensile Test: A tensile test is required to ensure the pipe meets the mechanical property requirements.

7. Sizes and Dimensions:

ASTM A106 pipes are available in nominal pipe sizes (NPS) ranging from 1/8 inch to 48 inches, with varying wall thicknesses depending on the pipe schedule (e.g., Schedule 40, Schedule 80).

8. Marking:

Each pipe must be marked with the manufacturer's name, specification number, grade, size, and heat number.

9. Heat Treatment:

Heat treatment is generally not required unless specifically requested by the purchaser. However, normalizing, quenching, and tempering can be applied depending on the desired mechanical properties.