Gate Valves — API 600 & API 602

What is a Gate Valve?

A gate valve shuts off flow with a wedge or parallel gate that slides between two seats at right angles to the flow. Fully open, the bore is almost unobstructed, so pressure drop is low. It is used for isolation, not throttling, because a partly open gate vibrates and erodes the seats. API 600 covers bolted-bonnet steel gate valves NPS 1–42 for refinery service; API 602 covers compact forged valves NPS 4 and smaller, typically Class 800 socket-weld or threaded for small-bore lines.

Key features

• API 600 bolted bonnet, outside screw and yoke (OS&Y), rising stem
• API 602 compact forged body, bolted, welded or pressure-seal bonnet
• Flexible wedge, solid wedge or parallel slide gate
• API 600 trims including 13Cr, Stellite hard-faced and 316
• Gear operator or actuator mounting on request

Specification

Applications

• Refinery and petrochemical process isolation
• Steam and boiler feed lines
• Oil and gas gathering and utility lines
• Small-bore instrument and drain isolation (API 602)
• Water and cooling water mains

API 600 vs API 602 gate valve

API 600 covers cast or forged bolted-bonnet gate valves NPS 1 to 42 in Class 150–2500 with flanged or butt-weld ends, used on process lines. API 602 covers compact forged gate, globe and check valves NPS 4 and smaller, including the intermediate Class 800 for socket-weld and threaded ends. For lines of NPS 2 and below, API 602 forged valves are the usual choice.