# 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. Understanding the differences between these standards is crucial for engineers, procurement specialists, and quality control professionals working in the oil and gas, power generation, and process industries.

## 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 refinery and pipeline service. It’s more specialized than ASME B16.34 and includes additional requirements for materials, design, and testing that are particularly relevant to the petroleum industry.

## Key Differences

### 1. Valve Types Covered

ASME B16.34 has a broader scope, applying to multiple valve types, while API 600 is exclusively for bolted bonnet steel gate valves.

### 2. Pressure-Temperature Ratings

Both standards provide pressure-temperature ratings, but API 600 includes additional requirements for extreme service conditions commonly encountered in oil refineries.

### 3. Material Requirements

API 600 has more stringent material specifications, particularly for components like stems and wedges, to ensure reliability in harsh refinery environments.

### 4. Testing Requirements

While both standards require pressure testing, API 600 includes additional tests such as backseat testing and shell testing at higher pressures.

### 5. Quality Control

API 600 mandates more rigorous quality control procedures and documentation requirements compared to ASME B16.34.

## When to Use Each Standard

ASME B16.34 is appropriate for general industrial applications across various valve types. API 600 should be specified when dealing with critical service gate valves in the petroleum industry where higher reliability and performance are required.

## Conclusion

Understanding the differences between ASME B16.34 and API 600 is essential for proper valve selection and specification. While ASME B16.34 provides general requirements applicable to many valve types, API 600 offers more specialized requirements for gate valves in demanding refinery services. Engineers should carefully consider the specific application requirements when deciding which standard to reference.