# ASME B16.34 vs. API 600: A Comparative Guide to Two Common Valve Standards

**Introduction: Navigating Valve Standards**
In the complex world of industrial valves, selecting the right standard is critical for safety, performance, and compliance. Two of the most frequently referenced and sometimes confused specifications are ASME B16.34 and API 600. This guide will clarify their purposes, highlight key differences, and help you make an informed choice for your application.

## **Core Purpose and Scope: What Do They Govern?**

**ASME B16.34: The Foundation for Pressure-Temperature Ratings**
This standard, published by the American Society of Mechanical Engineers (ASME), is foundational. It provides the **pressure-temperature ratings**, **wall thickness requirements**, and **material designations** for valves made from forgings, castings, and plate materials. Its scope is broad, covering gate, globe, check, ball, and plug valves in sizes NPS ½ through NPS 24. Essentially, B16.34 defines the **minimum design and wall thickness requirements** to ensure valves can safely contain pressure at specified temperatures.

**API 600: The Bolted Bonnet Steel Gate Valve Standard**
In contrast, API 600 is a product-specific standard from the American Petroleum Institute. It focuses exclusively on **bolted bonnet steel gate valves** for refinery and pipeline service. API 600 builds *upon* the requirements of ASME B16.34 but adds extensive, stringent criteria for **materials, dimensions, testing, and supplementary requirements** tailored for the demanding oil and gas industry. Think of API 600 as a detailed “buyer’s specification” for a specific valve type.

## **Key Differences: A Side-by-Side Comparison**

**Design and Construction Focus**
While ASME B16.34 sets the baseline design rules for pressure integrity, API 600 delves deeper into construction details. For example, API 600 mandates a **minimum stem diameter**, specific **bolting requirements**, and detailed criteria for **body/bonnet joints** and **gaskets**. An API 600 valve will always meet B16.34, but a B16.34 valve does not automatically comply with API 600.

**Material and Testing Requirements**
Material selection is another key differentiator. API 600 has very **prescriptive material requirements**, often dictating specific grades for body, bonnet, trim, and bolting. Its **testing protocols** are also more rigorous, requiring a **shell test, seat test, and backseat test** for every valve. ASME B16.34 references material specifications but is less prescriptive, focusing more on the design outcome.

**Application and Industry Usage**
This difference drives their typical applications. **ASME B16.34** is universally applied across power generation, chemical plants, and general industrial services. **API 600** is the go-to standard for **refineries, offshore platforms, and high-pressure hydrocarbon pipelines** where reliability under extreme conditions is non-negotiable. For a deeper dive into their distinctions, explore this resource on **two commonly asme b16 34 and api 600**.

## **Frequently Asked Questions (FAQ)**

**Can a valve be compliant with both ASME B16.34 and API 600?**
Yes, absolutely. In fact, an API 600 valve is required to conform to the design requirements of ASME B16.34. API 600 adds additional layers of requirements on top of that foundation.

**Which standard is more stringent?**
**API 600 is generally considered more stringent** for bolted bonnet steel gate valves. It imposes stricter material, design, and testing mandates tailored for severe service. ASME B16.34 provides the