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

March 20, 2025

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

## Introduction

When it comes to valve design and manufacturing, two standards stand out as the most commonly referenced in the industry: ASME B16.34 and API 600. While both standards provide guidelines for valve construction, they serve different purposes and have distinct requirements. This article explores the key differences and similarities between these two important standards.

## Overview of ASME B16.34

The ASME B16.34 standard is published by the American Society of Mechanical Engineers and covers the design, materials, dimensions, and testing requirements for valves. It applies to a wide range of valve types including gate, globe, check, ball, and butterfly valves.

Key features of ASME B16.34 include:

  • Pressure-temperature ratings for valve bodies

  • Wall thickness requirements

  • End-to-end dimensions

  • Materials specifications

  • Testing requirements

## Overview of API 600

API 600, published by the American Petroleum Institute, is specifically focused 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 valves used in demanding service conditions.

Key aspects of API 600 include:

  • Design requirements for bolted bonnet gate valves

  • Material specifications for severe service conditions

  • Fire-safe design requirements

  • Extended testing procedures

  • Quality control measures

## Key Differences Between the Standards

Scope and Application

ASME B16.34 has a broader scope, covering multiple valve types, while API 600 is specifically for bolted bonnet steel gate valves. API 600 is primarily used in oil and gas applications, whereas ASME B16.34 is more general-purpose.

Design Requirements

API 600 includes more stringent design requirements, particularly for:

  • Stem design (minimum diameter requirements)

  • Bonnet bolting (specific requirements for bolted connections)

  • Backseat design

  • Fire-safe features

Testing Requirements

While both standards require pressure testing, API 600 includes additional tests such as:

  • Shell and backseat tests at higher pressures

  • Optional fire testing

  • More rigorous quality control procedures

## Similarities Between the Standards

Despite their differences, ASME B16.34 and API 600 share several common elements:

  • Both reference ASME materials specifications

  • Both include pressure-temperature ratings

  • Both require non-destructive examination methods

  • Both specify marking and identification requirements

## Choosing Between the Standards

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

  1. Application: For general industrial use, ASME B16.34 may be sufficient. For oil and gas applications, API 600 is often required.

  2. Valve Type: If you need gate valves, API 600 provides more specific guidance. For other valve types, ASME B16.34 is