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Pressure Independent Control Valves Flow Verification/Commissioning Belimo’s Family of PI Control Valves ePIV PICCV © Belimo University 2012, All Rights Reserved Energy Valve Pressure Independent Control Valve What is a pressure independent control valve? A PI Control Valve…. Is a 2-way control valve that supplies a precise flow at any given control signal… Regardless of pressure variations in a system. It is not just a control valve and flow limiting circuit setter in the same assembly! Note: Automatic or manual balance valves should NOT be used with PI valves. If they are already installed they should be set WIDE OPEN. Pressure Independent Control Valve Field Installed P/T port requirements Additional P/T PORT for verification of 5 psi (11.5 ft H20) minimum differential across the PI Valve. Minimum ΔP across valve must be verified with PI valve COMMANDED by DDC (or by programming tool) to design flow, not manually positioned! System Level Flow Verification Step 1: Ensure all strainers are clean and bypass valves are closed. Step 2: Command via DDC all PI valves to design flow. (Diversity assumed at 100%.) Step 3: Set distribution pump(s) to elevated speed by commanding ΔP setpoint or pump speed directly. Step 4: Find the “critical zone” (ie. the PI valve that has the least ΔP). Step 5: Increase or decrease pump speed/ΔP setpoint until critical zone has just over 5 psid (11.5 ft H20). The resulting ΔP at the system sensor will be the optimum system ΔP setpoint. Step 6: Verify total system flow is at design at main flow station (or by other method). Step 7: If flow is not within +/- 10% of design, start checking valves at terminal level, starting with largest valve(s) first (voltage, control signal, strainer, etc.) Terminal Level Flow Verification • Belimo PI valves do NOT require that the entire system be placed in full design flow. Each PI valve flow can be verified individually with the rest of the system under normal control. 1) Command valve assembly to design. 2) Verify 5 psid across PI valve assembly. 3) Verify coil flow as per usual method (coil ΔP method, etc.) Link for PI valve commissioning document: www.piccv.com/pdf/PICCV_Application_Bulletin.pdf Belimo Field Programming Tool Field adjustable programming tool allows basic setup to be changed/modified based on initial or changing needs of project without hardware modification or change out. Example: Change Orders or Tenant Build outs. No external power needed; no battery; powered by actuator 24 vac. Just plug it into actuator. Belimo PC Tool Software Field Programming Software allows changes/modifications to setup in addition to trending and diagnostic capabilities. Commissioning Documentation Available upon request. Questions?