Calculation As per API-520

Calculation As per Dresser (1900)

Calculation As per Farris (2600)

Calculation As per Tai-Milano (3000W)

o To get Kd Value :

Calculate % back pressure = P2/Pset % & get Fh value from below graph

Multiply Kd as per table with Fh & then 0.9

So, Kd=Kd(table) x Fh x0.9