Understanding the API 598 Valve Testing Standard: A Guide for Engineers and Buyers

In the world of industrial valves—whether used in oil & gas, chemical, power generation, or water treatment—quality assurance is non-negotiable. One key international standard ensuring valve reliability is API 598. If you’re involved in specifying, purchasing, or manufacturing valves, understanding API 598 is essential.

📘 What Is API 598?

API 598 is the American Petroleum Institute’s standard for valve inspection and testing, covering leakage, pressure integrity, and shell testing for a variety of valve types including:

• Gate valves
• Globe valves
• Check valves
• Ball valves (where applicable)

It outlines procedures and acceptance criteria to confirm that valves meet minimum safety and reliability standards before being shipped to customers.

🧪 What Tests Are Required Under API 598?

API 598 specifies two major types of tests:

1. Shell Test (Hydrostatic)

• Purpose: Verifies the strength and structural integrity of the valve body and bonnet.
• How: Water (or compatible liquid) is used to apply pressure to the valve body with the valve in partially open position.
• Pressure: Typically 1.5x the rated pressure.

2. Seat Test (Leakage Test)

• Purpose: Ensures the valve properly seals when closed.
• How: Fluid is applied to either side of the closed valve to test for seat leakage.
• Pressure: Typically 1.1x the rated pressure.

3. Backseat Test (only for valves with a backseat)

• Purpose: Tests sealing capability between stem and bonnet when backseat is engaged.
• How: Internal pressure is applied with the stem in backseated position.
• Pressure: Typically 1.1x the rated pressure.

📌 Valve Types and Applicability

📌 Duration of Required Test Pressure

Why API 598 Compliance Matters

✅ Safety: Prevents catastrophic failures in high-pressure systems.
✅ Quality Assurance: Ensures leak-tight sealing performance.
✅ Procurement Confidence: Verifiable standard helps specifiers and buyers make informed decisions.
✅ Interoperability: Accepted globally, simplifies cross-border sourcing.

🏭 At Anson Flow, API 598 Comes Standard

At Anson Flow, we follow strict API 598 protocols across our OEM and private-label valve lines. Whether you're sourcing:

• 1-PC / 2-PC / 3-PC ball valves
• Gate, globe, or check valves
• Actuated valve packages

📩 Need Support?

If you're evaluating valve suppliers or want guidance on API 598-compliant components, contact us or email sales@ansonflow.com — our technical team is ready to help.