Comparison of ASME B16.34 and API 600 Standards for Valve Design

# Comparison of ASME B16.34 and API 600 Standards for Valve Design

## Introduction

When it comes to valve design and manufacturing, two of the most commonly referenced standards in the industry are ASME B16.34 and API 600. These standards provide guidelines for the design, materials, testing, and inspection of valves used in various industrial applications. While both standards serve similar purposes, they have distinct differences that engineers and procurement specialists should understand.

## Overview of ASME B16.34

The ASME B16.34 standard, developed by the American Society of Mechanical Engineers, is one of the most comprehensive standards for valve design. It covers:

• Pressure-temperature ratings
• Materials
• Dimensions
• Testing requirements
• Marking requirements

This standard applies to valves of all types, including gate, globe, check, ball, and butterfly valves, with flanged, threaded, or welding end connections.

## Overview of API 600

API 600, developed by the American Petroleum Institute, is specifically focused on bolted bonnet steel gate valves for petroleum and natural gas industries. Key aspects include:

• Design requirements for gate valves
• Material specifications
• Testing procedures
• Inspection requirements
• Marking and documentation

Unlike ASME B16.34, API 600 is more specialized and applies only to a specific valve type used in hydrocarbon service.

## Key Differences Between the Standards

Scope and Application

The most significant difference lies in their scope. ASME B16.34 is broader, covering various valve types across multiple industries, while API 600 is specifically for steel gate valves in petroleum applications.

Design Requirements

API 600 includes more detailed design requirements for gate valves, such as stem design, backseat provisions, and gland follower requirements. ASME B16.34 provides more general design guidelines applicable to multiple valve types.

Material Specifications

Both standards reference similar material grades, but API 600 includes additional requirements for material selection based on specific service conditions in the oil and gas industry.

Testing Requirements

API 600 generally has more stringent testing requirements, particularly for high-pressure applications, including extended shell tests and more rigorous seat leakage tests.

## When to Use Each Standard

The choice between these standards depends on the application:

• ASME B16.34 is appropriate for general industrial applications across various valve types
• API 600 should be specified for critical gate valve applications in petroleum and natural gas services

In many cases, valves may be designed to meet both standards, particularly for oil and gas applications where gate valves need to satisfy both general pressure requirements (ASME B16.34) and specific industry requirements (API 600).

## Conclusion

Understanding the differences between ASME B16.34 and API 600 is crucial for proper valve selection and specification. While ASME B16.34 provides comprehensive guidelines for various valve types, API 600 offers specialized requirements for gate valves in hydrocarbon service. Engineers should carefully consider the application requirements when deciding which standard to reference in their specifications.