Comparison of ASME B16.34 and API 600 Standards

# 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. While both standards address valve design and manufacturing, they serve different purposes and have distinct requirements. This article explores the key differences between these two important standards in the valve industry.

## Scope and Application

ASME B16.34

ASME B16.34 is a comprehensive standard that covers the design, materials, dimensions, testing, and inspection 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

API 600 specifically focuses on bolted bonnet steel gate valves for petroleum and natural gas industries. It’s more specialized than ASME B16.34 and includes additional requirements for materials, design, and testing that are specific to gate valves used in demanding service conditions.

## Key Differences

1. Valve Types Covered

ASME B16.34 is broader in scope, covering multiple valve types, while API 600 is exclusively for steel gate valves with bolted bonnets.

2. Pressure-Temperature Ratings

Both standards provide pressure-temperature ratings, but API 600 includes additional requirements for severe service conditions commonly encountered in oil and gas applications.

3. Material Requirements

API 600 has more stringent material specifications, particularly for components like stems, wedges, and seats that are critical in gate valve operation.

4. Testing Requirements

While both standards require pressure testing, API 600 includes additional tests like backseat testing and shell test duration requirements that exceed those in ASME B16.34.

## When to Use Each Standard

ASME B16.34 Applications

This standard is appropriate for general industrial applications across various valve types where basic design and performance requirements must be met.

API 600 Applications

API 600 should be specified for critical gate valve applications in the petroleum and natural gas industries, particularly for severe service conditions where higher reliability is required.

## Conclusion

While there is some overlap between ASME B16.34 and API 600, they serve different purposes in the valve industry. ASME B16.34 provides fundamental requirements applicable to various valve types, while API 600 offers specialized, more stringent requirements specifically for steel gate valves in demanding oil and gas service. Understanding these differences helps engineers and specifiers select the appropriate standard for their specific application needs.