Digital Valve Positioners
Description
Digital Valve Positioners are devices used to control the position of a valve by receiving an electronic signal from a controller and converting it into a pneumatic signal that adjusts the valve actuator. They are designed to ensure precise valve positioning, which is crucial for maintaining the desired set point in various process variables such as pressure, temperature, or flow.
Working Principle
Digital Valve Positioners operate by receiving an electric signal, typically ranging from 4-20mA, HART, PROFIBUS, or Foundation Fieldbus, from a controller. This signal is then converted into a corresponding pneumatic signal that is sent to the valve actuator. The positioner uses a microprocessor to monitor and adjust the valve position, ensuring high accuracy and efficiency. This closed-loop control system allows for precise valve positioning and reduces the use of compressed gas significantly compared to traditional analog positioners, as seen in the Siemens SIPART PS2 positioner, which uses 90% less compressed gas .
Applications
Digital Valve Positioners are widely used in industries where precise control of process variables is essential. For example, they are employed in chemical processing plants to maintain accurate flow rates and pressures. In the oil and gas industry, they help in controlling the flow of crude oil through pipelines, ensuring safety and efficiency. Additionally, they are used in water treatment facilities to regulate the flow and pressure of water through various stages of treatment.
Advantages over other Valve Positioners
Digital Valve Positioners offer several advantages over traditional analog and mechanical positioners. They provide greater precision in valve positioning, which is crucial for processes requiring high accuracy. They also consume significantly less compressed gas, reducing operational costs and environmental impact. The ability to monitor and record data allows for easy diagnostics and troubleshooting, minimizing downtime and maintenance efforts .
Limitations
Despite their advantages, Digital Valve Positioners have some limitations. They can be more expensive initially compared to traditional positioners due to their advanced technology and features. Additionally, they require a power supply and may be more complex to install and configure, necessitating skilled personnel for setup and maintenance.
Considerations
When considering the implementation of Digital Valve Positioners, it is important to evaluate the initial costs, which can be higher than traditional positioners. However, the reduction in operating expenses due to lower compressed gas usage and improved process efficiency can offset these costs over time. The durability and accuracy of digital positioners are generally superior, but they may require more frequent calibration and maintenance to ensure optimal performance. Replacement and maintenance costs should also be considered, as the advanced technology may necessitate specialized parts and expertise.
from DeZURIK, Inc.
The DeZURIK P30A Digital Positioner series offers intelligent and reliable valve control. The P30A is a robust, intelligent positioner with very high air capacity. Based on proven digital technology, it features a large, high-performance spool valve controlled by a unique intelligent control... [See More]
- Positioner Type: Digital
from Bonomi North America, Inc.
Basic Positioner for Double Acting Actuators [See More]
- Positioner Type: Digital
- Pneumatic Actuation: Double Acting Positioner
from Hamilton Company
The digital Modular Valve Positioner is controlled by equipment that has transistor-transistor logic, also known as TTL, or switch closure outputs. The serial Modular Valve Positioner is designed for applications that can utilize RS-232 serial communication. The serial protocol provides better error... [See More]
- Positioner Type: Digital
- Output Action: Direct Action
- Valve Actuation: Rotary
from DeZURIK, Inc.
The DeZURIK P85/SIPART PS2 is an electro-pneumatic positioner which has been providing safe and trouble-free operation in an extremely wide range of process industries worldwide for 20 years. The positioner – a multi-talent which can optimally handle a wide spectrum of challenges: whether in a... [See More]
- Positioner Type: Digital
from Bonomi North America, Inc.
Ex-proof Hart Positioner for Spring Return Actuators [See More]
- Positioner Type: Digital
from Hamilton Company
The serial Modular Valve Positioner is designed for applications that can utilize RS-232 serial communication. The serial protocol provides better error handling and diagnostics that are especially helpful in critical applications. With serial command, up to 16 serial Modular Valve Positioners can... [See More]
- Positioner Type: Digital
- Output Action: Direct Action
- Valve Actuation: Rotary
from Siemens Process Instrumentation
With the SIPART PS100 we extend our smart positioner portfolio. It is the right choice whenever you need a reliable controller for standard applications. Its ease and speed of initialization make it a winner for valve manufacturers, the chemical industry, the energy sector, and many other fields. [See More]
- Positioner Type: Digital
- Maximum Supply Pressure: 20.3 to 102
- Valve Actuation: Linear; Rotary
- Operating Temp: -4 to 176
from Burkert Fluid Control Systems
The compact positioner Type 8692 is optimized for integrated mounting on the pneumatic actuators in the process valve series Type 23xx/2103 and is specially designed for the requirements of a hygienic process environment. The control air channel is integrated in the actuator without external... [See More]
- Positioner Type: Digital
- Operating Temp: 14 to 131
- Valve Actuation: Linear
from Exlar
The SV Series Positioners were designed specifically for use with Exlar rotary and linear actuators to control valves and dampers in process control applications. The all-electric design eliminates the complexity of applying electro-hydraulic interface pilot valves or electric-pneumatic positioners,... [See More]
- Positioner Type: Digital; Electronic
- Milliampere Input Signal Range: 4 to 20
- Valve Actuation: Linear; Rotary
- Text for Other Electrical Input Signals: 0-10 VDC
from Siemens Process Instrumentation
The SIPART PS2 is the world ’s most widely used electropneumatic valve positioner for linear and part-turn actuators in industrial applications. The PS2 smart positioner is a reliable choice for a wide variety of valve control applications thanks to its advanced diagnostics and extensive range... [See More]
- Positioner Type: Electro-pneumatic (I / P); Digital
- Operating Temp: -22 to 176
- Valve Actuation: Linear; Rotary