Resources

Yokogawa Pressure Transmitters and Temperature Transmitters 2D & 3D CAD models

Unit Conversion Sites

Yokogawa HART and BRAIN Pocket Guides

Control Valve Sizing Program

Safety Relief Valve Sizing Program

Digital Yewflo Vortex Flow Meter Sizing Program

ANSI Pressure Ratings

Yokogawa General Specification Data Sheets

Valve Seat Leakage Chart
The Fluids Control Institute (FCI) Standard ANSI/FCI 70.2 establishes a Valve’s allowable seat Leakage Rate. The standard recognizes five degrees of seat tightness.

 

Valve Seat Leakage Chart

The Fluids Control Institute (FCI) Standard ANSI/FCI 70.2 establishes a Valve’s allowable seat Leakage Rate. The standard recognizes five degrees of seat tightness.

ALLOWABLE SEAT LEAKAGE CLASSES Leakage Class

Maximum Seat Leakage

Test Fluid

Test Pressure

Relative Seat Tightness

Class II 0.5% of rated CV

Water

45 to 60 PSI

1.0

Class III 0.1% of rated CV

Water

45 to 60 PSI

5.0

Class IV 0.01% of rated CV

Water

45 to 60 PSI

50

Class IV+ 0.0015 ml /min/inch of trim size/ ΔP(PSI)

Water

Max Operating ΔP

150,000

Class V 0.0005 ml /min/inch of trim size/ ΔP(PSI)

Water

Max Operating ΔP

300,000

Class VI about 0.9 ml/min ∗

Air

50 PSI

600,000