leakage rate
ISO 5208 vs API 598: Valve Leakage Testing Compared
How ISO 5208 and API 598 differ in scope, leakage grades, test media, test pressure and directionality — and how to reference them correctly in a valve purchase specification.
valve testing
valve testing
Control Valve Seat Leakage Classes: ANSI/FCI 70-2 Class
A practical guide to ANSI/FCI 70-2 seat leakage classes for control valves — test conditions, Class IV defaults, Class VI soft seats, and how to specify the right class without overpaying.
seat lapping
Valve Reconditioning: What a Proper Refurbishment Includes
A complete look at professional valve reconditioning — teardown assessment, dimensional checks, seat overlay, stem recovery, testing, coatings and documentation.