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

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

## Introduction

In the world of industrial valve manufacturing, two standards stand out as the most widely recognized and implemented: ASME B16.34 and API 600. While both standards govern valve design and construction, they serve different purposes and have distinct requirements. This article explores the key differences between these two important standards.

## Understanding ASME B16.34

The ASME B16.34 standard, developed by the American Society of Mechanical Engineers, provides comprehensive requirements for:

– Pressure-temperature ratings
– Dimensions
– Materials
– Testing
– Marking

This standard applies to a wide range of valve types including gate, globe, check, ball, and butterfly valves in sizes NPS ½ through NPS 24.

## Understanding API 600

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

– Design requirements
– Material specifications
– Testing procedures
– Inspection criteria
– Documentation requirements

## Key Differences Between the Standards

### Scope and Application

ASME B16.34 has a broader application across various industries, while API 600 is specifically tailored for the oil and gas sector. The table below highlights some key differences:

Feature | ASME B16.34 | API 600

Valve Types | Multiple (gate, globe, ball, etc.) | Primarily gate valves
Industry Focus | General industrial applications | Petroleum and natural gas
Size Range | NPS ½ to NPS 24 | Typically NPS 2 to NPS 24

### Material Requirements

ASME B16.34 references materials listed in ASME Boiler and Pressure Vessel Code, while API 600 has its own specific material requirements with additional toughness testing for low-temperature applications.

### Testing Requirements

Both standards require pressure testing, but API 600 includes more stringent requirements:

– Longer duration for shell tests
– Additional testing for low-pressure closures
– Specific requirements for seat leakage tests

## Choosing Between the Standards

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

– Industry requirements
– Operating conditions
– Customer specifications
– Regulatory compliance needs

For general industrial applications, ASME B16.34 may be sufficient, while API 600 is typically required for critical service in the oil and gas industry.

## Conclusion

Both ASME B16.34 and API 600 play crucial roles in ensuring valve quality and performance. While they share some common ground, their differences reflect their distinct purposes and industry focuses. Understanding these differences helps engineers and procurement specialists make informed decisions when specifying valves for their applications.