Schedule 80 Pipe Dimensions in mm & Inches: Size Chart

Schedule 80 Pipe Dimensions vary according to the nominal pipe size. Schedule 80 is a pipe wall designation that generally indicates a heavier wall than Schedule 40 for the same nominal pipe size. The outside diameter remains based on the nominal pipe size, while the thicker wall results in a smaller inside diameter.

Schedule 80 Steel Pipe Dimensions in mm include the nominal pipe size (NPS), outside diameter (OD), wall thickness, and inside diameter (ID). For example, a 2-inch Schedule 80 pipe has an outside diameter of 60.3 mm and a nominal wall thickness of 5.54 mm (0.218 inch).

This guide provides a detailed Schedule 80 Steel Pipe Dimensions Chart covering common pipe sizes, outside diameter, wall thickness, and approximate inside diameter in millimetres and inches.

Schedule 80 Pipe is a pipe with a heavier nominal wall thickness than Schedule 40 pipe for the same nominal pipe size. The schedule number identifies a pipe wall series rather than one fixed wall thickness for every pipe size.

The actual Schedule 80 pipe dimensions depend on the Nominal Pipe Size (NPS). As the NPS changes, the outside diameter and nominal wall thickness also change. Because Schedule 80 has a thicker wall than Schedule 40 for the same applicable NPS, its inside diameter is generally smaller.

Schedule 80 pipe is commonly selected when a heavier pipe wall is required. The appropriate pipe size, material grade, manufacturing specification, operating temperature, and design conditions should be considered before selecting a pipe for a particular application.

Schedule 80 steel pipe dimensions in mm are determined by the nominal pipe size and its corresponding outside diameter and nominal wall thickness. The approximate inside diameter can be calculated by subtracting twice the wall thickness from the outside diameter.

The Schedule 80 pipe pressure rating is not a single fixed pressure value that applies to every Schedule 80 pipe. The allowable working pressure depends on several factors, including pipe material, grade, nominal pipe size, wall thickness, operating temperature, allowable stress, design code, and applicable product specification.

Schedule 80 pipe has a thicker nominal wall than Schedule 40 for the same nominal pipe size. The additional wall thickness generally provides greater pressure-handling capability under comparable design conditions. However, the schedule designation alone should not be used to determine the maximum allowable working pressure.

For example, a 2-inch Schedule 80 pipe has a nominal outside diameter of 60.3 mm and a nominal wall thickness of 5.54 mm. Its pressure capacity cannot be determined from these dimensions alone because the material grade, design temperature, allowable stress, corrosion allowance, and applicable design code must also be considered.

For engineering applications, the allowable working pressure should be determined using the applicable piping code and material specification. The calculation should consider operating temperature, allowable stress, corrosion allowance, manufacturing tolerances, joint efficiency where applicable, and other project-specific design requirements.

Therefore, Schedule 80 should be understood primarily as a pipe dimensional or wall-thickness series designation, not as a universal pressure class. Always verify the required pressure rating with the applicable standard, material specification, and engineering design before selecting the pipe.

A Pipe Schedule Chart helps identify the nominal wall thickness series used for different pipe sizes. Common pipe schedules include Schedule 10, Schedule 40, Schedule 80, and Schedule 160. The applicable schedules and dimensions depend on the nominal pipe size and the dimensional standard being used.

The schedule number does not represent a fixed wall thickness in millimetres. The nominal wall thickness changes according to the Nominal Pipe Size (NPS). Therefore, a Schedule 40 or Schedule 80 pipe can have different wall thicknesses at different pipe sizes.

For the same nominal pipe size, a higher schedule generally indicates a thicker nominal wall and a smaller inside diameter. For example, a 2-inch Schedule 40 pipe has a nominal wall thickness of 3.91 mm, while a 2-inch Schedule 80 pipe has a nominal wall thickness of 5.54 mm.

The outside diameter (OD) for the same NPS generally remains unchanged when comparing different schedules, while the increased wall thickness reduces the available inside diameter (ID).

For exact pipe dimensions, always refer to the applicable dimensional standard and the specific NPS and schedule rather than treating the schedule number as a direct wall-thickness measurement.

The Schedule 40 vs Schedule 80 inside diameter is different for the same nominal pipe size because Schedule 80 has a thicker wall. Although the corresponding outside diameter remains the same, the thicker Schedule 80 wall reduces the available internal opening.

For example, a 2-inch pipe has an outside diameter of 60.3 mm. A 2-inch Schedule 40 pipe has a nominal wall thickness of 3.91 mm, giving an approximate inside diameter of 52.5 mm. A 2-inch Schedule 80 pipe has a nominal wall thickness of 5.54 mm, giving an approximate inside diameter of 49.2 mm.

The approximate inside diameter can be calculated using the following formula:

ID = OD − (2 × Wall Thickness)

Therefore, when comparing pipes of the same nominal size, Schedule 80 has a smaller inside diameter than Schedule 40. The exact dimensions should always be verified against the applicable pipe dimensional standard and product specification.

• Schedule 80 pipe has a heavier nominal wall than Schedule 40 for the same nominal pipe size.
• Schedule 80 pipe dimensions vary according to the Nominal Pipe Size (NPS).
• The outside diameter is based on the nominal pipe size, while the wall thickness determines the approximate inside diameter.
• Schedule 80 pipe thickness in mm changes according to the NPS and should be taken from the applicable dimensional standard.
• Schedule 80 does not have one universal pressure rating. Pressure capacity depends on material, temperature, dimensions, design code, and other engineering factors.
• Always verify the pipe specification, material grade, dimensions, and applicable standard before selecting pipe for an engineering application.