ANSI/FCI Standard 70-2

ANSI/FCI Standard 70-2, from the American National Standards Institute and the Fluid Controls Institute, defines leakage classifications specifically for control valves.

Scope

ANSI/FCI 70-2 is the industry standard for control valve leakage.

Classifications

ANSI/FCI 70-2 defines six classifications of control valve leakage, providing test procedures and the maximal allowable leakage (MAL) for each.

Class

MAL

Test medium

Test pressure

I
Not specified No test required No test required
II
0.5% rated capacity Air or water at 50°F to 125°F Lower of 45 to 60 psig or maximum operating differential
III
0.1% rated capacity Same as Class II Same as Class II
IV
0.01% rated capacity Same as Class II Same as Class II
V
0.0005 ml per minute of water per inch of port diameter per psi differential: “Effectively zero leakage” Water at 50°F to 125°F Maximum service pressure across valve plug not to exceed ANSI rating
VI
Milliliters or bubbles per minute based on nominal port diameter Air at 50°F to 125°F Lower of 50 psig or maximum rated pressure across valve plug

 

A full copy of ANSI/FCI 70-2 can be purchased from the American National Standards Institute

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