DTV Flow Calculator Use the below calculations to determine Cv when hot effluent flow rate is known: 1. Determine the required cold water flow (CW) needed to temper the hot effluent. HOT EFFLUENT FLOW RATE (HF) GPM HOT EFFLUENT TEMPERATURE (HT) °F MAX. ALLOWABLE DRAIN TEMPERATURE (MT) °F MAX. COLD WATER TEMPERATURE (CT) °F CW GPM 2. Calculate Cv required to flow that much cold water. COLD WATER PRESSURE (CP) PSIG Cv Refer to the DTV Cv chart below to determine the correct size DTV to use. DTV WATER INLET SIZE (NPT) Cv 1/2" 2.0 3/4" 2.0 1" 4.0 If hot effluent flow rate is unknown, but the cold water pressure is known then use the below calculation to determine the maximum achievable effluent flow rate for the 1/2", 3/4", & 1" DTV. 1. Determine the cold water flow rate. DTV WATER INLET SIZE 1/2″ & 3/4″ NPT DTV WATER INLET SIZE 1″ NPT Cv 2.0 Cv 4.0 CP PSIG CP PSIG Effluent PSIG Effluent PSIG CW GPM CW GPM 2. Determine the maximum effluent flow achievable. DTV WATER INLET SIZE 1/2″ & 3/4″ NPT DTV WATER INLET SIZE 1″ NPT MT °F MT °F CT °F CT °F HT °F HT °F HF GPM HF GPM