Understanding API Valve Standards: 600, 602, 608, 6D Complete Guide

April 2, 2026 10 min read Supreme Valves India

The American Petroleum Institute (API) standards define the design, manufacturing, and testing requirements for industrial valves used in oil, gas, and petrochemical applications. Understanding which API standard applies to your valve selection is critical for compliance, performance, and reliability. This guide explains the key API valve standards and their applications.

API Valve Standards Overview

API 600 - Steel Gate Valves

Also known as: ISO 17292, API 600 (bolt bonnet steel gate valves)

Scope: Bolted bonnet gate valves (wedge, double-disc, parallel-slide, knife-gate) in sizes NPS 1/2 through NPS 60, pressure classes 150 through 2500.

Application: General industrial service, refinery, petrochemical, power plant, and process industry applications. The most widely specified gate valve standard.

API 602 - Compact Steel Valves

Also known as: ISO 15761

Scope: Compact forged steel gate, globe, check, and ball valves in sizes NPS 1/4 through NPS 4, pressure classes 150 through 1500 (or 2500 for some designs).

Application: Instrument hook-ups, sampling systems, small-bore piping, and applications where compact design and lighter weight are important.

API 608 - Steel Ball Valves

Also known as: ISO 17292的一部分

Scope: Floating ball valves (quarter-turn) in sizes NPS 1/2 through NPS 12, pressure classes 150 through 600.

Application: Refinery and general industrial service where bubble-tight shutoff is required. Does not cover trunnion mounted ball valves.

API 6D - Pipeline Valves

Also known as: ISO 14313

Scope: Pipeline valves including gate, ball, check, and plug valves in sizes NPS 1 through NPS 56, pressure classes 150 through 2500.

Application: Pipeline transmission, storage, and distribution systems. Covers both floating and trunnion mounted ball valves, as well as other pipeline valve types.

API Standards Comparison Table

Standard Valve Type Size Range Pressure Classes Primary Use
API 600 Gate (wedge, double-disc) NPS 1/2 - NPS 60 150 - 2500 Refinery, process, power
API 602 Gate, globe, check, ball (forged) NPS 1/4 - NPS 4 150 - 1500/2500 Compact applications, instruments
API 608 Ball (floating) NPS 1/2 - NPS 12 150 - 600 General industrial ball valves
API 6D Gate, ball, check, plug NPS 1 - NPS 56 150 - 2500 Pipeline transmission

When to Use Each API Standard

API 600 - Steel Gate Valves

Specify API 600 when you need bolted bonnet gate valves for standard industrial applications. API 600 gate valves are the workhorse of refinery and process plant piping systems. They provide reliable isolation for hydrocarbon service, steam systems, water, and general process applications.

Typical specifications: "Gate valve shall be API 600, bolted bonnet, WCB body, Class 300, RF flanged ends, OS&Y, Stellite trim."

API 602 - Compact Forged Steel Valves

Specify API 602 for smaller size valves where space is limited or weight is a concern. These forged steel valves are commonly used in:

API 608 - Steel Ball Valves

Specify API 608 for floating ball valves in general industrial service. API 608 covers the most common ball valve configuration and is widely specified across industries. When you need fire-safe ball valves, specify API 607 in addition to API 608.

Typical specifications: "Ball valve shall be API 608, floating ball design, CF8M body, Class 150, RF flanged, PTFE seats, API 607 fire-safe."

API 6D - Pipeline Valves

Specify API 6D for all pipeline applications including:

API 6D includes additional requirements for fugitive emissions, fire-safe testing, and pipeline-specific testing that are not covered by API 608.

Fire-Safe Standards: API 607 and API 6FA

Fire-safe certification verifies that a valve will maintain its sealing capability during and after exposure to fire. This is critical for oil & gas, offshore, and fire protection applications.

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Frequently Asked Questions

What is the difference between API 600 and API 6D?

API 600 (ISO 17292) covers bolted bonnet steel gate valves for general industrial service. API 6D (ISO 14313) covers pipeline valves including gate, ball, and check valves for pipeline service. API 6D valves have additional requirements for fire-safe design, pressure testing, fugitive emissions, and dimensional compatibility with flanges. For pipeline applications, API 6D is typically specified.

When should I specify API 602 instead of API 600?

API 602 covers compact forged steel valves (gate, globe, check, ball) in sizes NPS 1/4 to NPS 4. Use API 602 for smaller valve applications (up to 4 inches) where compact design and lighter weight are important, such as instrument hook-ups, sampling systems, and small-bore piping. API 600 covers larger bolted bonnet valves.

What does fire-safe API 607 mean for ball valves?

API 607 is a fire-safe test standard that verifies a quarter-turn valve (including ball valves) maintains tight shutoff during and after exposure to fire. The valve uses graphite or special seats that remain functional even when organic seat materials burn. Fire-safe certification is mandatory for ball valves in oil & gas, offshore, and fire protection applications.

Which API standard covers trunnion mounted ball valves?

Trunnion mounted ball valves are covered under API 6D (ISO 14313) - the Pipeline Valve Standard. While API 608 covers floating ball valves, API 6D specifically addresses the design, testing, and documentation requirements for trunnion mounted ball valves used in pipeline service, including larger sizes and higher pressure classes.

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