Let s keep it simple. Electronic Valves

Transcription

1 UNDERSTANDING ELECTRONIC CONTROLLED HYDRAULICALLY OPERATED VALVES Presented by: Donica Webb Regional Sales Manager OCV Control Valves 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 1

2 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. 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 2

3 SO HOW DOES THIS COMPARE WITH VALVES? Heat & Air System Set Point = Temperature Controller = Thermostat Manual / Programmable Heating/Cooling Air Unit Temperature Sensor output to thermostat Air Duct Water System Set Point = Pressures, flows, level Controller = PLC Programmable logic Dual Solenoid Valve Transducer- 4-20mA signal to controller Water Pipe 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 3

4 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 SO HOW DOES THIS COMPARE WITH VALVES? Heat & Air System Set Point = Temperature Controller = Thermostat Manual / Programmable Heating/Cooling Air Unit Temperature Sensor output to thermostat Air Duct Water System Set Point = Pressures, flows, level Controller = PLC Programmable logic Dual Solenoid Valve Transducer- on the pipe 4-20mA signal to controller Water Pipe 4

5 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 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 OPENING SPEED A B SOLENOID A-closing SOLENOID B-opening VALVE ACTION Closed Open Starts Opening Closed Closed Holds Position Open Closed Starts Closing 5

6 SO HOW DOES THIS COMPARE WITH VALVES? Heat & Air System Set Point = Temperature Controller = Thermostat Manual / Programmable Heating/Cooling Air Unit Temperature Sensor output to thermostat Air Duct Water System Set Point = Pressures, flows, level Controller = PLC Programmable logic Dual Solenoid Valve Transducer- on the pipe 4-20mA signal to controller Water Pipe 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 Constant tank or filter level Pressure Level Upstream of valve At base of tank or filter Positioning Valve Position Transmitter On valve cover Uses valve stem travel 6

7 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? PRESSURE REDUCING 22R 7

8 BACK PRESSURE 22S FLOW RATE 1 22F 8

9 TANK or FILTER LEVEL Flow into Tank = Flow out of Tank 1 POSITIONING 22X 1 9

10 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 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 10

11 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 AUTOMATION & ADAPTABILITY 11

12 AUTOMATION & ADAPTABILITY FLOW CONTROL Gravity flow from reservoir Valves control flow rate into treatment plant flow rates vary AUTOMATION & ADAPTABILITY POSITIONING VALVE Valves positioned open % to discharge excess plant water into aquifer recharge basin Municipality may receive pumping credit for aquifer recharging 12

13 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= MGAL 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 13

14 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 QUESTIONS? 14

15 Thank You For Attending Donica Webb OCV Control Valves, LLC 15