A Universal Differential Pressure Transmitter
The VEGADIF 85 is designed as a flexible differential pressure measurement solution rather than a transmitter limited to a single application. By measuring the pressure difference between two process connections, it can be used for different process variables depending on the installation and associated primary elements.
VEGA lists applications including level measurement in pressurized vessels, flow measurement, filter monitoring, density measurement and interface measurement.
Designed for Liquids, Gases and Vapours
The VEGADIF 85 can be applied to a broad range of process media, including liquids, gases and vapours. This makes it suitable for process systems where differential pressure is used as the basis for determining another process variable.
Reliable Measurement with an Integrated Overload Diaphragm
One of the key design features of the VEGADIF 85 is its integrated overload diaphragm. VEGA identifies this as an important factor contributing to measurement reliability, particularly for differential pressure applications where pressure conditions can vary between the two sides of the measuring cell.
Suitable for Very Low Differential Pressures
The transmitter is designed for precise measurement of very low differential pressures. This is particularly useful in applications such as flow measurement, filter monitoring and other processes where relatively small pressure differences need to be detected accurately.
Differential Pressure for Pressurized Vessel Level Measurement
For vessels operating under pressure, the VEGADIF 85 can determine liquid level by measuring the pressure difference between the vessel's lower and upper pressure points.
This makes it suitable for applications where the vessel pressure must be taken into account rather than relying only on hydrostatic pressure.
Flow Measurement with Primary Flow Elements
The VEGADIF 85 can be used for flow measurement together with suitable primary flow elements. The pressure difference generated across the primary element provides the differential pressure signal from which flow can be determined.
Filter Monitoring
Differential pressure across a filter can provide an indication of increasing resistance or filter loading. The VEGADIF 85 can therefore be integrated into filter monitoring systems where the pressure difference between the upstream and downstream sides is the relevant process variable.
Multivariable Measurement Capability
A notable feature of the VEGADIF 85 is its ability to incorporate absolute pressure measurement in addition to differential pressure. VEGA describes this as providing a multivariable sensor configuration, which can be useful where both pressure values are relevant to the measurement task.
Flexible Process Connections and Materials
The VEGADIF 85 can be configured with threaded or flanged process connections for installation on vessels and piping. Depending on configuration, wetted materials include 316L, Alloy C276, gold and Superduplex, allowing the transmitter to be matched to different process requirements.
Flexible Communication and Adjustment
Depending on the selected version, the VEGADIF 85 supports 4–20 mA/HART, PROFIBUS PA, FOUNDATION Fieldbus or 4–20 mA output options. Configuration and adjustment can also be carried out through compatible VEGA display, PC/software, HART and Bluetooth solutions, depending on the selected configuration.
Key Features
- Product type: Differential pressure transmitter
- Universal measurement of differential pressure
- Suitable for liquids, gases and vapours
- Applications for level, flow, filter monitoring, density and interface measurement
- High-precision measurement of low differential pressures
- Integrated overload diaphragm
- Optional integrated absolute pressure measurement
- Threaded and flanged process connections
- Wetted materials including 316L, Alloy C276, gold and Superduplex, depending on configuration
- 4–20 mA/HART, PROFIBUS PA, FOUNDATION Fieldbus and 4–20 mA options depending on configuration
- PLICSCOM and VEGADIS display/adjustment options
- Bluetooth adjustment available depending on configuration
- IP66/IP67 or IP66/IP68 protection options
- ATEX, FM, IEC, CSA, UKEX, INMETRO and other approvals available depending on configuration
- SIL2 qualification available
- DNV and GL ship approvals available depending on configuration
Typical Applications
Level Measurement in Pressurized Vessels
The VEGADIF 85 can measure liquid level in vessels where pressure is present above the liquid surface. Differential pressure measurement compensates for the pressure acting on the vessel and provides the basis for hydrostatic level measurement.
Flow Measurement
When installed with a suitable primary flow element, the VEGADIF 85 can be used to measure flow based on the differential pressure generated by the element. This makes it suitable for conventional differential-pressure flow measurement systems.
Filter Monitoring
Monitoring the pressure difference across a filter can help identify increasing pressure loss as the filter becomes loaded. The VEGADIF 85 can be installed between the upstream and downstream sides of the filter for this type of measurement.
Density Measurement
Differential pressure can be used to determine liquid density when the measurement arrangement and process conditions are suitable. The VEGADIF 85 supports this type of application as part of its broader differential pressure measurement capabilities.
Interface Measurement
For applications involving two immiscible liquids with different densities, differential pressure measurement can be used to determine the position of the interface. The VEGADIF 85 is designed to support this type of measurement.
Hydraulic and Process Systems
The transmitter can also be applied to hydraulic and process systems where differential pressure provides useful information about pressure loss, flow or process conditions. VEGA specifically presents hydraulic oil station applications for the VEGADIF 85.
Reverse Osmosis Systems
Differential pressure monitoring is relevant to reverse osmosis installations, where pressure differences across process components can provide important operating information. VEGA lists reverse osmosis as an application for the VEGADIF 85.
FAQ
What is the VEGA VEGADIF 85?
The VEGADIF 85 is a universal differential pressure transmitter designed to measure differential pressure for applications such as level, flow, filter monitoring, density and interface measurement.
What can the VEGADIF 85 measure?
The VEGADIF 85 measures differential pressure and can use that measurement principle for determining level, flow, density and interface position, as well as monitoring pressure differences across filters.
Can the VEGADIF 85 measure level?
Yes. It can be used for level measurement in pressurized vessels, where the pressure difference between the vessel's upper and lower measurement points is used to determine liquid level.
Can the VEGADIF 85 be used for flow measurement?
Yes. The VEGADIF 85 can be combined with suitable primary flow elements for differential pressure flow measurement.
Can it measure density?
Yes. Density measurement is one of the applications listed by VEGA for the VEGADIF 85. The suitability depends on the complete measurement arrangement and process conditions.
Does the VEGADIF 85 measure absolute pressure?
The primary measurement is differential pressure, but the VEGADIF 85 can be configured with integrated absolute pressure measurement, giving it multivariable measurement capability.
What communication options are available?
Depending on configuration, the VEGADIF 85 is available with 4–20 mA/HART, PROFIBUS PA, FOUNDATION Fieldbus or 4–20 mA output options.
Can the VEGADIF 85 be used in hazardous areas?
Yes. VEGA lists approvals including ATEX, FM, IEC, CSA, UKEX and INMETRO, with the exact approval depending on the selected configuration.
Is the VEGADIF 85 suitable for high-temperature applications?
The official product page lists process temperatures from -90 to 400°C, depending on the selected configuration. Chemical seals and the complete installation must be considered when selecting a configuration for high-temperature service.
What is the difference between VEGADIF 85 and a standard pressure transmitter?
A standard pressure transmitter measures pressure relative to a reference, while the VEGADIF 85 is designed primarily to measure the difference between two process pressures. This makes it suitable for applications such as pressurized-vessel level, differential-pressure flow and filter monitoring.
