Viscous Liquid Correction Factor (Kv) adjusts relief valve capacity calculations for viscous fluids. This correction accounts for reduced flow efficiency in laminar flow conditions, ensuring accurate sizing for high-viscosity liquids.
API Standard 520 Part I requires viscosity correction when Reynolds number is below 10,000. The correction factor applies to liquid relief calculations per ASME BPVC Section VIII. Typical Kv values range from 0.2 (very viscous) to 1.0 (non-viscous).
Without viscosity correction, relief valves for viscous liquids may be undersized, failing to provide adequate overpressure protection. This calculation prevents dangerous situations in industries handling heavy oils, polymers, and other viscous fluids.
Viscosity correction is essential for accurate relief valve sizing in viscous service. This calculation ensures proper overpressure protection while accounting for real-world fluid behavior. Always verify results against valve manufacturer data for specific applications.