Tag Archive: valve

Dec
08

Using Wireless Throttling Valves in Column Control

At Emerson Exchange 2014 I worked with Stephen Briggs, University Of Texas, Austin and Kurtis Jensen, Emerson Process Management, to co-host a workshop on control using a wireless throttling valve. As addressed in this presentation, we have tested in a flow lab the control performance that may be achieved using PIDPlus with a wireless throttling …

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Mar
31

Wireless Throttling Valve Power Consumption

Control to Minimize Changes in Target Valve Position

Something that all manufactures of wireless throttling valves must be concerned with in their design is battery power consumption. In a control application using a wireless throttling valve much of the power available to the actuator is used to track changes in target valve position. To minimize battery power consumption, the number of changes made …

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Mar
24

Utilizing Wireless Throttling Valves in Control

Rev_PID vs PIDPlus in Control Using Wireless Valve

Over the last five years a wide variety of WirelessHART transmitters have been introduced by the major manufacturers of field devices. The PIDPlus enables closed loop control using the slower update rate provided by a wireless transmitter. The broad acceptance of wireless transmitters has generated an interest in the application of wireless throttling valves in …

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Mar
17

Flow Control – Positive Displacement Pump Part 2

Positive Displacement Pump Flow Control With Throttling Valve

When using a positive displacement pump in flow control, then the minimum flow which may be achieved using a variable speed drive is limited by the motor low speed limit. It is possible to achieve a wider range of flow control by regulating flow using a fixed speed motor and a throttling valve in combination …

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Mar
03

Flow Control – Centrifugal Pump

Flow Control Using Centrifugal Pump

Centrifugal pumps can be used to transfer large volumes of liquid between vessels in an industrial process. When a constant speed motor is used to drive the pump then the pump flow rate may be controlled by adjusting a throttling valve that is installed after the pump discharge, as illustrated below. The pump discharge pressure …

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Feb
03

WirelessHART – Monitoring and Control of On-Off Valves

TopWorx_4310

A number of WirelessHART devices have been introduced over the last few years to monitor the status of on/off valves. For example, the TopWorx 4310 WirelessHART Valve Position Monitor can be used detect linear and rotary movement using non-contact technology with limit switch feedback. Such devices provide a low cost way to monitor the position …

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Oct
14

Control Using Wireless Measurements

Control Using Wireless Measurements

During the initial development of WirelessHart we began researching how to address control applications that use a wireless measurement and/or wireless actuator. To extend battery life a wireless transmitter may be setup to communication the measurement value much slower than the update rate of a wired installation. Also, when the transmitter supports Window communications (as …

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Mar
18

Impact of Changing Process Gain

non-linear valve characteristics

From a control perspective, it is highly desirable that the process gain is constant. If the process gain is constant, then the same proportional gain can be used over the entire operating range of the control loop. Using a control valve as an example, if the valve characteristic was not properly selected based on the …

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Mar
11

Evaluating Valve/Actuator Performance

Impact of Sticky Valve on Control

When a control loop is placed in automatic control, it is easy to detect if a valve or actuator is not responding correctly to the control system. As discussed in Chapter 3 of Advanced Control Foundation – Tools, Techniques and Application, this can be done by observing the response of the controlled parameter to control …

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Aug
27

Addressing Control Applications Using WirelessHART Devices

EmersonExchange2012

At Emerson Exchange, 2012 I will be co-presenting a workshop with Mark Nixon and Marty Zielinski titled Addressing Control Applications Using WirelessHART Devices. In this workshop we will be address the technical basis for the PID modification, known as PIDPlus, that are included in DeltaV v11 to address control using the non-period, slow measurement updates …

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