I D
× COMMENTARYCOVER STORYIN THE NEWSNEWSFRONTSCHEMENTATOR + Show More
Chemical Engineering MagazineChementator Briefs
Sulfur control Preferential Oxidation Catalysis — a new catalytic solution…
BUSINESS NEWS
Chemical Engineering MagazineBusiness News
Plant Watch Perstorp will construct new plant for sodium formate…
TECHNICAL & PRACTICALFEATURE REPORTFACTS AT YOUR FINGERTIPSTECHNOLOGY PROFILEEQUIPMENT & SERVICESFOCUSNEW PRODUCTS + Show More SHOW PREVIEWS

Comment PDF Environment, Health, Safety & Security

Engineering Practice: Discharge Coefficients and Flow Resistance Factors

By Dilip Das Bayer CropScience |

This article presents the fundamental concepts of the discharge coefficient, KD, of a relief valve or a safety relief valve, and flow resistance factor, KR, of a rupture disk, and their proper use in sizing an emergency relief system. When these devices are used to protect a pressure vessel, they must be certified according to ASME code in the U.S. Both the discharge coefficient and the flow resistance factor are dimensionless numbers determined by measurement and theoretical computation. These factors are prescribed in Performance Test Code (PTC) 25 of ASME VIII, Division 1. Discharge Coefficient The discharge coefficient of a relief valve or safety relief valve is the ratio of the measured relieving capacity of the valve to its theoretical relieving capacity computed by a prescriptive theoretical equation matching the test fluid, test pressure, temperature and flow area of the valve. In the determination of the discharge coefficient, there is a choice of the test fluid among steam, air, gas or water. The deviation of the discharge coefficient from the value of unity comes from the deficiency of either the flow model (mass flux through the valve as a function of density and pressure) or the fluid model (density as a function of pressure),…
Related Content
Focus on Valves
Rotary valve controls the flow of powders and granules The Coperion ZRD Heavy-Duty Premium rotary valve (photo) is designed for…
Reactive Chemistry in the CPI
Reactive chemicals and intermediates are used extensively in the chemical process industries (CPI). Hazardous chemical reactivity can be defined as…

Chemical Engineering publishes FREE eletters that bring our original content to our readers in an easily accessible email format about once a week.
Subscribe Now
Quadruple Sensor Lifetime with a Retractable Housing
Minimizing Explosion Risk Where Other Solutions Cannot
Minimizing Corrosion with Fast, Robust Gas Analysis
Lower Measurement Point Costs with Automatic pH Sensor Cleaning
Reduce the Risk of Corrosion in Fertilizer Production

View More

Live chat by BoldChat