Electric Bicycle,Electric Fat Bike,Cheap Electric Bike FOSHAN GUANSEN BICYCLE TECHNOLOGY CO.,LTD. , https://www.fshedatxbike.com1, C: The volume of water flowing through the valve per hour (expressed in m3) when the valve is fully open with water at 5 "40 ° C and the differential pressure across the valve 1kgf / cm2. 2, Kv: When the valve is fully open, the temperature of 5 "40 ℃ water, valve pressure across the 100KPA, the hourly flow through the valve volume (m3). Kv = 1.01C, currently recommended in our country. 3, Cv: The volume of water (expressed in m3) flowing through the valve per hour at a pressure differential of 1 lb / in2 at 15 ° C (60 ° F) with full valve open. Cv = 1.167C