🔍 What Is MAOP and How Do You Calculate It Correctly?

🚧 What Is MAOP?

Maximum Allowable Operating Pressure (MAOP) is the highest pressure at which a pipeline can safely operate under regulated conditions. Determining the MAOP is critical to ensure safe operation, avoid failure, and comply with design codes such as ASME B31.8 or ASME B31.4.

Improper MAOP settings can lead to pipeline ruptures, fines, or catastrophic failures.

📏 What Affects MAOP?

Several key factors determine a pipeline’s MAOP:

Pipe Material Yield Strength (SMYS)
Wall Thickness
Pipe Diameter
Weld Joint Factor
Design Factor (Location Class)
Corrosion Allowance or Defect Depth
Applicable Design Code

🔧 Common Design Code Approaches

🛠 ASME B31.8 (Gas Pipelines)

MAOP = (2 * t * SMYS * F * E * T) / D

t: wall thickness
D: outside diameter
F: design factor (depends on location class)
E: weld joint factor
T: temperature derating factor

🛢 ASME B31.4 (Liquid Pipelines)

MAOP = (2 * t * SMYS) / D, adjusted by test factors and conditions

🔍 Corroded pipelines or those with damage must use reduced pressure estimates, often involving corrosion depth ratios or defect interaction rules.

⚙️ How to Calculate MAOP Easily

Instead of wrestling with spreadsheets, you can use our powerful online calculator built for gas and liquid pipelines.

✅ Supports:

Gas or liquid pipeline selection
Design code selection (B31.4, B31.8)
Corroded and uncorroded sections
SI and US Customary units
Corrosion defect depth calculations

🔧 Try it here → Pipeline MAOP Calculator

💡 Related Tools

If you’re working with MAOP, you’ll also benefit from:

Wall Thickness Calculator – For design validation
Corrosion Rate & Remaining Life – To determine future pressure limits
Pipeline Corrosion Defect MAOP – For localized corrosion assessments

🧰 Need Help Applying This?

We provide industry-grade tools and consulting to support your MAOP verifications and upgrades.
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🔍 What Is MAOP and How Do You Calculate It Correctly?