# Comparison of ASME B16.34 and API 600 Standards

Introduction

When it comes to industrial valves, two commonly referenced standards are ASME B16.34 and API 600. These standards provide guidelines for the design, materials, and testing of valves used in various industries. While they share some similarities, there are distinct differences between them that engineers and procurement specialists should understand.

Scope and Application

ASME B16.34 is a comprehensive standard that covers the design, materials, dimensions, and testing requirements for valves with flanged, threaded, and welding end connections. It applies to a wide range of valve types including gate, globe, check, ball, and butterfly valves.

API 600, on the other hand, is more specific, focusing exclusively on bolted bonnet steel gate valves for petroleum and natural gas industries. It’s considered a more stringent standard for this particular valve type.

Key Differences

1. Valve Types Covered

ASME B16.34 is broader in scope, covering multiple valve types, while API 600 is limited to bolted bonnet steel gate valves.

2. Pressure-Temperature Ratings

Both standards provide pressure-temperature ratings, but API 600 typically requires valves to meet more demanding service conditions common in oil and gas applications.

3. Material Requirements

API 600 has more specific material requirements, particularly for body and bonnet materials, to ensure suitability for harsh hydrocarbon service.

4. Testing Requirements

API 600 generally has more rigorous testing requirements, including extended shell test durations and more stringent seat leakage criteria.

When to Use Each Standard

Choose ASME B16.34 when you need a general standard applicable to various valve types across different industries. It’s particularly useful when valves will be used in non-hydrocarbon services or when flexibility in valve selection is needed.

Opt for API 600 when specifying bolted bonnet steel gate valves for critical hydrocarbon services, especially in the oil and gas industry where more stringent requirements are necessary for safety and reliability.

Conclusion

While both ASME B16.34 and API 600 are important valve standards, they serve different purposes. ASME B16.34 provides general requirements for a wide variety of valves, while API 600 offers specialized, more rigorous specifications for bolted bonnet steel gate valves in hydrocarbon service. Understanding these differences helps ensure proper valve selection for specific applications.