Let`s Keep It Simple. Electronic Valves

Transcript

UNDERSTANDING ELECTRONIC CONTROLLED HYDRAULICALLY OPERATED VALVES Presented by: Donica Webb Regional Sales Manager OCV Control Valves Global performance. Personal touch. Let’s keep it simple. Electronic Valves • Everyday Interaction with Electronic Systems • The Controller • The Valve • How the Valve Communicates • What, Why, Where and When • Automation & Adaptability • Applications Global performance. Personal touch. 1 Let’s keep it simple. Everyday electronics. • We don’t need the technical electronic details. • We need to know how to operate them. • We really only want the results. Global performance. Personal touch. Let’s keep it simple. TOO HOT – TOO COLD Heat & Air System Set Point = Temperature Controller = Thermostat Manual / Programmable Heating/Cooling Air Unit Temperature Sensor output to thermostat Air Duct Global performance. Personal touch. 2 SO HOW DOES THIS COMPARE WITH VALVES? Heat & Air System Water System Set Point = Temperature Set Point = Pressures, flows, level Controller = Thermostat Manual / Programmable Controller = PLC Programmable logic Heating/Cooling Air Unit Dual Solenoid Valve Temperature Sensor output to thermostat Transducer- 4-20mA signal to controller Air Duct Water Pipe Global performance. Personal touch. THE SYSTEM A CLOSER LOOK – The Controller • PLC – Programmable Logic Controller • Programmable to the application • • • • • • Set Points Time scheduling Logging & Totalizing Alarms Defaults Reporting communication • Typical Types • Touch screen – color • Key pad with display Global performance. Personal touch. 3 THE SYSTEM A CLOSER LOOK – Controller - Operation • Stores the set point • Receives input for set point changes • Receives 4-20mA signal from transducer of condition • Compares set point to condition • Sends electrical voltage pulse to solenoids • Changes valve position when condition does not meet set point • Sends communication of set point status, alarms, other data Global performance. Personal touch. SO HOW DOES THIS COMPARE WITH VALVES? Heat & Air System Water System Set Point = Temperature Set Point = Pressures, flows, level Controller = Thermostat Manual / Programmable Controller = PLC Programmable logic Heating/Cooling Air Unit Dual Solenoid Valve Temperature Sensor output to thermostat Transducer- on the pipe 4-20mA signal to controller Air Duct Water Pipe Global performance. Personal touch. 4 THE SYSTEM A CLOSER LOOK – The Control Valve CLOSING SPEED OPENING SPEED • Line pressure opens/closes valve • Inlet pressure pushes up to open valve • Pressure OFF diaphragm open • Inlet on diaphragm closes • Pressure ON diaphragm closes • Opening & closing speed is adjustable Global performance. Personal touch. THE SYSTEM A CLOSER LOOK – The Control Valve • Voltage is sent from the controller to the solenoids when conditions don’t meet the set point • Solenoids are pulsed until set point is reached CLOSING SPEED A SOLENOID A-closing SOLENOID B-opening VALVE ACTION Closed Open Starts Opening Closed Closed Holds Position Open Closed Starts Closing OPENING SPEED B Global performance. Personal touch. 5 SO HOW DOES THIS COMPARE WITH VALVES? Heat & Air System Water System Set Point = Temperature Set Point = Pressures, flows, level Controller = Thermostat Manual / Programmable Controller = PLC Programmable logic Heating/Cooling Air Unit Dual Solenoid Valve Temperature Sensor output to thermostat Transducer- on the pipe 4-20mA signal to controller Air Duct Water Pipe Global performance. Personal touch. Let’s keep it simple. How do you do it? SENSING DEVICE • Transducer • Converts a physical property to an electrical signal • milliamps 4 – 20 mA • The great the mA the higher the reading • Example: 4mA = 0 PSI while 20mA = 200 PSI • Example: 4mA = 0 GPM while 20mA = 500 GPM • Actual ranges vary according to application • Where you put the transducer determines the function. APPLICATION TRANSDUCER LOCATION Flow Control Flow Meter with 4-20mA output Meter location User discretion Pressure Reducing Pressure Downstream of valve Backpressure Sustaining Pressure Upstream of valve Constant tank or filter level Level At base of tank or filter Positioning Valve Position Transmitter On valve cover Uses valve stem travel Global performance. Personal touch. 6 Let’s keep it simple • What do you control in your system? • • • • • DOWNSTREAM PRESSURE UPSTREAM PRESSURE FLOW RATE TANK LEVEL POSITIONING • What is your set point? • • • • PSI GPM MGD FEET SO HOW DOES THIS WORK WITH VALVES? Global performance. Personal touch. PRESSURE REDUCING 22R Global performance. Personal touch. 7 BACK PRESSURE 22S Global performance. Personal touch. FLOW RATE 22F 1 Global performance. Personal touch. 8 TANK or FILTER LEVEL Flow into Tank = Flow out of Tank 1 Global performance. Personal touch. POSITIONING 22X 1 Global performance. Personal touch. 9 SO WHY ELECTRONIC VALVES? AUTOMATION • Set points are easily changed • Remotely – you don’t have to be there • Unlimited settings (no spring ranges) • Simple valve sizing • Control is over wide flow range • Valve locked in position at set point • Control features can be programmed • Valve scheduling capable • Feedback Communication • System status w/ alarms • Analog & Digital Global performance. Personal touch. SO WHY ELECTRONIC VALVES? ADAPTABILITY • Wide range of control applications • Electronic control • Combined with hydraulic pilot system backup • Combined with multiple transducers • Programs can be written for unique needs • Easy to modify at installation Global performance. Personal touch. 10 AUTOMATION & ADAPTABILITY •Storage tank in distribution system receives water from high service pumping system •Valve maintains desired upstream pressure on distribution which varies by time and season demand •Storage tank overflow is protected by hydraulic altitude pilot which overrides electronic backpressure function Global performance. Personal touch. AUTOMATION & ADAPTABILITY Global performance. Personal touch. 11 AUTOMATION & ADAPTABILITY FLOW CONTROL •Gravity flow from reservoir •Valves control flow rate into treatment plant – flow rates vary Global performance. Personal touch. AUTOMATION & ADAPTABILITY POSITIONING VALVE • Valves positioned open % to discharge excess plant water into aquifer recharge basin •Municipality may receive pumping credit for aquifer recharging Global performance. Personal touch. 12 AUTOMATION & ADAPTABILITY FLOW METERING • • Meters flow rate (no control) Can be combined with other hydraulic functions: • Pressure reducing • Backpressure control • Altitude Flow= 2122 GPM TOT= 00001.925 MGAL Global performance. Personal touch. AUTOMATION & ADAPTABILITY FLOW METERING AND CONTROL •Existing Venturi meter and pump station •System expansion required flow control to Zone B •Valve meters flow rate and controls flow rate to zone B set by water district Global performance. Personal touch. 13 AUTOMATION & ADAPTABILITY WELL COMMANDER • Controlled by a Tri-Plex controller • One controller for 3 wells • Turns each pumps on/off • Each valve is set for individual flow rate • Prevents over pumping of the wells by monitoring each well level Global performance. Personal touch. QUESTIONS? Global performance. Personal touch. 14 Thank You For Attending Donica Webb OCV Control Valves, LLC www.controlvalves.com Global performance. Personal touch. 15