# 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 play crucial roles in ensuring the safety, reliability, and performance of valves used in various industries. While both standards address valve design and manufacturing, they have distinct focuses and applications.

## Overview of ASME B16.34

ASME B16.34 is a comprehensive standard developed by the American Society of Mechanical Engineers that covers valves with flanged, threaded, and welding end connections. This standard applies to a wide range of valve types, including:

– Gate valves

– Globe valves
– Check valves
– Ball valves
– Butterfly valves

The standard specifies requirements for pressure-temperature ratings, materials, dimensions, and testing for valves intended for use in petroleum refineries, chemical plants, and related industrial applications.

## Overview of API 600

API 600 is a standard developed by the American Petroleum Institute that specifically focuses on bolted bonnet steel gate valves for refinery use. This standard is more specialized than ASME B16.34 and includes requirements for:

– Design features
– Material specifications
– Face-to-face dimensions
– Pressure testing
– Inspection requirements

API 600 valves are typically used in more demanding applications where reliability is critical, such as in oil and gas production and refining operations.

## Key Differences Between the Standards

### Scope and Application

ASME B16.34 has a broader scope, covering multiple valve types and connection methods, while API 600 is specifically focused on bolted bonnet steel gate valves. ASME B16.34 is more widely applicable across industries, whereas API 600 is primarily used in the petroleum and natural gas industries.

### Pressure-Temperature Ratings

Both standards provide pressure-temperature ratings, but they approach them differently. ASME B16.34 offers a more generalized approach, while API 600 provides specific ratings tailored to refinery applications.

### Material Requirements

API 600 has more stringent material requirements, particularly for components like stems and wedges, which must meet specific toughness and hardness criteria. ASME B16.34 provides more flexibility in material selection.

### Testing Requirements

API 600 includes more rigorous testing requirements, including extended shell tests and more comprehensive seat leakage tests compared to ASME B16.34.

## Choosing Between the Standards

The choice between ASME B16.34 and API 600 depends on several factors:

– Industry requirements (API 600 is often specified in oil and gas)
– Valve type needed
– Operating conditions
– Customer specifications
– Regulatory requirements

In many cases, valves can be designed to meet both standards simultaneously, providing the benefits of each specification.

## Conclusion

While ASME B16.34 and API 600 both serve important roles in valve standardization, they cater to different needs within the industry. ASME B16.34 provides a broad foundation for various valve types, while API 600 offers specialized requirements for critical applications in the petroleum industry. Understanding the differences between these standards helps engineers and procurement specialists make informed decisions when specifying valves for their projects.