Contact

Siemens SITRANS P320 Pressure Transmitter: SIL 2/3, Technical Specifications, MLFB and Replacement Guide

...
Siemens SITRANS P320 Pressure Transmitter: SIL 2/3, Technical Specifications, MLFB and Replacement Guide
Siemens SITRANS P320 Pressure Transmitter: SIL 2/3, Technical Specifications, MLFB and Replacement Guide

🛠️Siemens SITRANS P320 Pressure Transmitter: SIL 2/3, Technical Specifications, MLFB and Replacement Guide

What Is the Siemens SITRANS P320?

The Siemens SITRANS P320 is a digital pressure transmitter designed for industrial process pressure measurement. Depending on the configuration, it can be used for gauge pressure, absolute pressure and differential pressure measurement in gases, vapors and liquids.

Depending on the selected configuration, the SITRANS P320 can also be applied to level, volumetric flow and mass flow measurement. Siemens specifies a measuring range of 10 mbar to 700 bar, depending on the version and measuring cell. The maximum stated accuracy for the P320 is up to 0.065%.

One of the key advantages of the P320 is not limited to measurement performance. The product family combines digital communication, NAMUR NE107 diagnostics, Remote Safety Handling and functional safety capabilities for demanding process automation applications.


SITRANS P320 Technical Specifications

Technical Specification SITRANS P320
Product type Digital pressure transmitter
Measurement types Gauge, Absolute, Differential Pressure
Additional applications Level, volumetric flow, mass flow
Measuring range 10 mbar–700 bar, depending on version and measuring cell
Accuracy Up to 0.065%, depending on configuration
Response time Down to 105 ms
Long-term stability ≤ 0.125% / 5 years
Communication 4–20 mA + HART, PROFIBUS PA, FOUNDATION Fieldbus
Digital communication PROFINET over Ethernet-APL, depending on version
Diagnostics NAMUR NE107
Functional Safety IEC 61508, SIL 2/3 applications
Remote Safety Handling Supported
Proof-test interval Up to 15 years for suitable safety configurations
Measured medium temperature -40 to +100 °C, depending on configuration
Approvals ATEX, IECEx, FM, CSA, NEPSI and others, depending on configuration
Diaphragm options Various materials depending on application
Housing Industrial process transmitter design

Siemens specifies the main P320/P420 performance figures according to product version and configuration. Therefore, the exact MLFB and technical configuration should always be verified before ordering.


SITRANS P320 Measurement Types

Gauge Pressure

Gauge pressure measurement determines process pressure relative to atmospheric pressure.

SITRANS P320 gauge pressure configurations can be used in applications such as:

  • Process pipelines

  • Pumps

  • Compressors

  • Gas systems

  • Steam lines

  • Pressure vessels

  • Process equipment

Gauge pressure is generally selected when atmospheric pressure is the required reference for the measurement.


Absolute Pressure

Absolute pressure measurement uses absolute vacuum as the reference rather than atmospheric pressure.

This makes absolute pressure suitable for applications where atmospheric pressure variations should not influence the measurement, including:

  • Vacuum processes

  • Low-pressure applications

  • Distillation systems

  • Vacuum pumps

  • Process control systems


Differential Pressure

Differential pressure measurement determines the pressure difference between two process points.

Depending on the configuration, the SITRANS P320/P420 family can be used for:

  • Filter monitoring

  • Flow measurement

  • Tank level measurement

  • Process pressure differential monitoring

  • Pump and equipment performance monitoring

Differential pressure measurement is particularly important in process applications where the pressure difference between two points represents a process variable.


SITRANS P320 MLFB and Product Code

For Siemens products, the MLFB (Machine-Readable Product Designation) is critical for identifying the exact ordering configuration.

"SITRANS P320" represents the product family. It does not, by itself, define the complete orderable configuration.

The following parameters may need to be evaluated:

  • Measurement type

  • Measuring cell

  • Measuring range

  • Process connection

  • Diaphragm material

  • Fill fluid

  • Electrical connection

  • Communication protocol

  • Hazardous-area certification

  • Display

  • Special options

A Siemens P320 HART operating document shows an example nameplate with an MLFB in the format 7MF0350-1G*01-5BF0-Z. The * character represents a placeholder within the documentation example and should not be treated as a complete orderable MLFB by itself.

For PROFIBUS PA and FOUNDATION Fieldbus versions, Siemens documentation identifies the following P320 product families:

  • 7MF03.1 – SITRANS P320 PROFIBUS PA

  • 7MF03.2 – SITRANS P320 FOUNDATION Fieldbus

Why Is the Complete MLFB Important?

Different SITRANS P320 configurations can include different:

  • Measuring ranges

  • Pressure types

  • Process connections

  • Diaphragm materials

  • Communication protocols

  • Hazardous-area approvals

  • Electrical connections

Therefore, an RFQ based only on "Siemens P320" or a shortened product-family designation can create a risk of selecting the wrong configuration.

The complete MLFB should be verified against the Siemens documentation and the project specification before ordering.


SITRANS P320 Accuracy and Measurement Performance

Siemens specifies the SITRANS P320 with up to 0.065% accuracy under suitable conditions and configurations.

This should not be interpreted as a fixed accuracy value for every P320 configuration.

Actual performance can depend on:

  • Measuring cell

  • Nominal measuring range

  • Configured span

  • Turndown ratio

  • Measurement type

  • Process conditions

  • Ambient conditions

For engineering specifications, it is therefore preferable to verify the exact accuracy for the selected configuration rather than simply stating that every P320 provides 0.065% accuracy.


SITRANS P320 Long-Term Stability and Response Time

Siemens specifies a response time of down to 105 ms and long-term stability of ≤ 0.125% over 5 years for the P320/P420 family, depending on the applicable configuration.

These characteristics can be particularly relevant for:

  • Fast process control

  • Pressure fluctuation monitoring

  • Critical control loops

  • Chemical processes

  • Energy applications

  • Process automation systems

Actual performance should always be evaluated against the selected configuration and operating conditions.


SITRANS P320 Communication Protocols

The SITRANS P320 family supports several communication technologies for integration into process automation systems.

4–20 mA + HART

4–20 mA + HART is widely used in conventional process automation architectures.

HART communication enables digital access to device information in addition to the analog process signal.

Depending on the configuration, this can provide access to:

  • Device parameters

  • Diagnostic information

  • Configuration data

  • Measurement values

  • Device status


PROFIBUS PA

PROFIBUS PA is a digital fieldbus technology widely used in process automation.

Siemens documentation identifies 7MF03.1 as the SITRANS P320 PROFIBUS PA product family.

This makes the P320 suitable for process automation architectures using PROFIBUS PA field-level communication, subject to the selected configuration.


FOUNDATION Fieldbus

For FOUNDATION Fieldbus versions, Siemens documentation identifies 7MF03.2 as the SITRANS P320 FOUNDATION Fieldbus product family.

Therefore, an RFQ should specify the required communication protocol instead of simply requesting a "SITRANS P320."


PROFINET over Ethernet-APL

Siemens' current P320/P420 product information also lists PROFINET over Ethernet-APL among the available communication technologies.

Ethernet-APL is particularly relevant to modern process automation architectures that require Ethernet-based communication at the field level.

The availability of this communication option should be verified against the exact P320 configuration before ordering.


SITRANS P320 and SIL 2/3 Functional Safety

The SITRANS P320 is designed to support SIL 2/3 applications in accordance with IEC 61508, depending on the applicable configuration and safety architecture.

An important distinction should be made between saying:

"The P320 is SIL 2/3 certified."

and:

"The P320 supports SIL 2/3 applications when used in an appropriate configuration and safety system architecture."

The second statement is technically more appropriate because the achieved SIL capability depends not only on the transmitter but also on:

  • Device configuration

  • Safety function

  • Safety architecture

  • Proof-test procedures

  • PFD/PFH calculations

  • IEC 61508 requirements

  • IEC 61511 application requirements

For safety-related projects, the applicable Siemens safety documentation should therefore be reviewed together with the complete project safety requirements.


What Is Remote Safety Handling?

One of the key features of the SITRANS P320/P420 family is Remote Safety Handling.

Depending on the system architecture, this functionality can support:

  • Device configuration

  • Maintenance activities

  • Safety-related functions

  • SIL validation processes

from the control room.

Siemens positions Remote Safety Handling as a solution that can help reduce field visits, minimize personnel exposure in hazardous areas and simplify commissioning and maintenance activities.

This can be particularly valuable in large process plants where hundreds of field transmitters may need to be configured, verified or maintained.


Proof-Test Interval

For suitable safety applications, the P320/P420 family can support proof-test intervals of up to 15 years.

A longer proof-test interval can have a positive impact on:

  • Maintenance planning

  • Shutdown organization

  • Field access requirements

  • Maintenance workload

  • Total cost of ownership

However, a 15-year interval should not be interpreted as an automatic maintenance interval for every application.

The applicable proof-test interval must be established according to the plant's safety lifecycle, safety calculations and applicable standards.


NAMUR NE107 Diagnostics

The SITRANS P320/P420 family supports NAMUR NE107 diagnostics.

NAMUR NE107 provides a standardized approach for classifying device status information, helping maintenance personnel identify equipment conditions more efficiently.

Depending on the diagnostic condition, maintenance teams can more easily distinguish between:

  • Device failures

  • Maintenance requirements

  • Process-related conditions

  • Device status conditions

This can improve troubleshooting and predictive maintenance strategies in process automation systems.


SITRANS P320 Industrial Applications

The SITRANS P320 can be used across a wide range of industrial sectors.

Chemical Industry

Potential applications include:

  • Reactor pressure

  • Process pipelines

  • Tank pressure

  • Differential pressure

  • Level measurement

Petrochemical and Refining

Pressure transmitters are commonly required for:

  • Process columns

  • Pumps

  • Compressors

  • Pipelines

  • Storage tanks

  • Filters

Power Generation

Potential applications include:

  • Steam systems

  • Feedwater systems

  • Auxiliary processes

  • Pressurized gas systems

  • Differential pressure measurement

Gas and Industrial Gas Systems

In gas applications, reliability, correct pressure range selection and appropriate hazardous-area certification can be critical.

The P320's diagnostics and functional safety capabilities can be relevant where these requirements apply.

Water and Wastewater

Depending on the configuration, the P320 can be used for:

  • Pump pressure

  • Pipeline pressure

  • Filter differential pressure

  • Tank level


SITRANS P320 for Level Measurement

Differential pressure measurement can be used to determine liquid level based on the hydrostatic pressure generated by a liquid column.

A suitable P320 configuration can therefore be considered for:

  • Closed tanks

  • Pressurized vessels

  • Process vessels

  • Chemical storage tanks

The application should take into account:

  • Tank geometry

  • Liquid density

  • Temperature

  • Static pressure

  • Process connections

For high-temperature, corrosive or crystallizing media, options such as remote seals may need to be considered.


SITRANS P320 for Flow Measurement

Differential pressure can also be used for flow measurement when the transmitter is combined with an appropriate primary flow element.

Examples include:

  • Orifice plates

  • Venturi tubes

  • Flow nozzles

The resulting differential pressure can be measured using an appropriate differential-pressure configuration.

This creates additional commercial search opportunities around terms such as:

  • Siemens P320 differential pressure transmitter

  • Siemens P320 DP transmitter

  • Siemens P320 flow measurement

  • Siemens P320 level measurement

  • SITRANS P320 HART

  • SITRANS P320 PROFIBUS PA

  • SITRANS P320 FOUNDATION Fieldbus


How to Select the Right SITRANS P320

Selecting the correct P320 requires more than simply specifying a pressure range.

The following parameters should be evaluated together.

1. Measurement Type

  • Gauge Pressure

  • Absolute Pressure

  • Differential Pressure

2. Measuring Range

Define:

  • Minimum process pressure

  • Normal operating pressure

  • Maximum operating pressure

3. Overpressure and MAWP

Maximum allowable working pressure and test pressure should be checked in addition to the normal operating pressure.

4. Process Connection

Depending on the application, options may include:

  • Threaded connections

  • Flanges

  • Remote seals

  • Other process-specific configurations

5. Wetted Parts and Diaphragm Material

Material selection should consider:

  • Corrosive media

  • Process temperature

  • Chemical compatibility

  • Solids or particulate content

6. Communication

Specify the required communication technology:

  • HART

  • PROFIBUS PA

  • FOUNDATION Fieldbus

  • Ethernet-APL, where applicable

7. Hazardous-Area Certification

For hazardous-area applications, the required approvals should be checked, such as:

  • ATEX

  • IECEx

  • FM

  • CSA

8. Functional Safety

If the transmitter is used in a safety instrumented function, the complete safety architecture must be evaluated rather than relying solely on the product's SIL designation.

9. Display and Local Operation

Determine whether local display and local operating functionality are required.

10. Complete MLFB

Finally, all selected options should be validated against the complete MLFB before an order is placed.


SITRANS P320 Commissioning Checklist

The following checks can be used during commissioning:

  • Complete MLFB verified

  • Measurement type verified

  • Measuring range verified

  • Process connection checked

  • Diaphragm material compatible with the process

  • Communication protocol verified

  • Supply voltage checked

  • 4–20 mA loop wiring checked

  • HART / fieldbus addressing configured

  • Zero point checked

  • Required calibration completed

  • Hazardous-area certification verified

  • SIL application requirements verified where applicable

  • NAMUR NE107 diagnostics checked

  • DCS / PLC / SIS integration tested

  • Process connections checked for leakage

  • Commissioning documentation completed


SITRANS P320 Troubleshooting Guide

No 4–20 mA Signal

Check:

  1. Supply voltage

  2. Loop wiring

  3. Polarity

  4. Ex barrier / galvanic isolator

  5. Cable continuity

  6. Device diagnostic information

  7. Electrical configuration


Measurement Value Remains Constant

Check:

  • Is the actual process pressure changing?

  • Is the impulse line blocked?

  • Is the valve manifold correctly positioned?

  • Is the sensor connection correct?

  • Is damping configured appropriately?

  • Is the transmitter reporting a diagnostic condition?

For differential-pressure applications, particular attention should be given to the impulse lines and manifold.


Measurement Value Appears Incorrect

Possible causes include:

  • Incorrect measuring range

  • Incorrect zero adjustment

  • Incorrect process connection

  • Process temperature effects

  • Incorrect diaphragm selection

  • Pressure pulsations

  • Impulse line problems

  • Incorrect transmitter configuration


HART Communication Cannot Be Established

Check:

  • Loop resistance

  • HART modem

  • Device power supply

  • Polling/address configuration

  • HART-compatible infrastructure

  • Wiring

  • Device communication version

  • DCS/PLC integration


SITRANS P320 vs. P420

Feature SITRANS P320 SITRANS P420
Product class Digital pressure transmitter Premium digital pressure transmitter
Maximum accuracy Up to 0.065% Up to 0.04%
Measuring range 10 mbar–700 bar, depending on version 10 mbar–700 bar, depending on version
Communication HART / PROFIBUS PA / FOUNDATION Fieldbus HART / PROFIBUS PA / FOUNDATION Fieldbus
Functional Safety SIL 2/3 applications SIL 2/3 applications
NAMUR NE107 Yes Yes
Remote Safety Handling Yes Yes
Proof-test Up to 15 years Up to 15 years
Advanced digital functionality Advanced More advanced
Trend recording Up to 1,500 measured values
Typical positioning General and critical process applications Higher accuracy and advanced digitalization requirements

According to Siemens product information, the P320 can provide accuracy of up to 0.065%, while the P420 can provide up to 0.04%. The P420 also provides onboard trend recording for up to 1,500 measured values.

Therefore, the P420 should not automatically be considered a direct replacement for every P320 application. The selection should be based on accuracy, process requirements, digital functionality, communication and safety requirements.


SITRANS P DS III and P410 Replacement with P320

The SITRANS P320 is particularly relevant in modernization projects involving older Siemens pressure transmitters.

Siemens Industry Mall identifies various SITRANS P DS III / P410 products as canceled products and indicates P320/P420 as successor products for applicable configurations.

However, this transition should not be treated as a simple one-to-one MLFB substitution.

For a P DS III or P410 replacement project, the existing transmitter should first be evaluated for:

  • Complete MLFB

  • Measurement type

  • Measuring range

  • Process connection

  • Diaphragm material

  • Communication protocol

  • Hazardous-area certification

  • Remote seal configuration

  • SIL requirements

The appropriate P320 or P420 configuration can then be determined.

This approach reduces the risk of selecting an unsuitable replacement based solely on the product family name.


How to Determine a SITRANS P320 Replacement

A practical replacement workflow is:

Existing transmitter → Complete MLFB → Technical parameter extraction → Process requirement verification → P320/P420 configuration → New MLFB → Certification and documentation check → RFQ

If an older Siemens transmitter is being replaced with a P320, simply stating:

"Replace the existing device with a P320."

is not sufficient.

A technical cross-reference should be performed first.

This makes search terms such as Siemens P320 replacement, SITRANS P320 MLFB, SITRANS P DS III replacement and Siemens pressure transmitter replacement commercially valuable for modernization and procurement projects.


Frequently Asked Questions

What is the Siemens SITRANS P320?

The SITRANS P320 is a digital Siemens pressure transmitter for measuring pressure in gases, vapors and liquids. Depending on the configuration, it can also be used for differential pressure, level and flow applications.

What is the accuracy of the SITRANS P320?

Siemens specifies up to 0.065% accuracy for suitable P320 configurations. The actual accuracy depends on the measuring cell, span and operating conditions.

What pressure ranges does the SITRANS P320 support?

The P320/P420 family supports measuring ranges from 10 mbar to 700 bar, depending on the version and measuring cell.

Does the SITRANS P320 support HART?

Yes. Appropriate P320 configurations support 4–20 mA + HART communication.

Does the SITRANS P320 support PROFIBUS PA?

Yes. Siemens documentation identifies 7MF03.1 as the SITRANS P320 PROFIBUS PA product family.

Does the SITRANS P320 support FOUNDATION Fieldbus?

Yes. Siemens documentation identifies 7MF03.2 as the SITRANS P320 FOUNDATION Fieldbus product family.

Can the SITRANS P320 be used in SIL 2/3 applications?

Yes. Siemens specifies IEC 61508-based support for SIL 2/3 applications. Actual SIL suitability depends on the device configuration, safety function and complete safety system architecture.

What is the difference between SITRANS P320 and P420?

The P420 is positioned as the higher-performance model, with higher available accuracy and additional digital functionality. Siemens specifies up to 0.065% accuracy for the P320 and up to 0.04% for the P420.

Can SITRANS P320 replace SITRANS P DS III?

For applicable discontinued P DS III/P410 configurations, Siemens identifies P320/P420 as successor products. However, replacement should be performed based on the complete existing MLFB and application requirements rather than by product-family name alone.

Why is the SITRANS P320 MLFB important?

Because "P320" identifies the product family, while the complete MLFB determines the specific configuration, including measuring cell, range, process connection, materials, communication, certification and other options.


Yeşil Grup Enerji – Independent Siemens SITRANS P320 Sourcing

Yeşil Grup Enerji is not an official Siemens distributor or authorized Siemens representative.

Yeşil Grup Enerji operates as an independent, brand-independent industrial sourcing supplier, supporting project-based procurement and global sourcing requirements for industrial instrumentation and automation products.

For Siemens SITRANS P320 procurement, the objective is not simply to provide a product name or generic model reference. The correct technical configuration should first be identified according to the customer's project requirements.

Yeşil Grup Enerji can support the SITRANS P320 sourcing process with:

  • SITRANS P320 MLFB verification

  • Technical cross-reference of existing Siemens transmitters

  • P320 / P420 replacement evaluation

  • Gauge / Absolute / Differential Pressure selection review

  • Measuring range and measuring cell verification

  • HART / PROFIBUS PA / FOUNDATION Fieldbus configuration review

  • Process connection and material verification

  • Ex / ATEX / IECEx and other certification requirement checks

  • Technical review for SIL-related applications

  • Technical documentation and configuration checks

  • Project-based RFQ

  • International global sourcing

  • International procurement and supply coordination for projects outside Türkiye

The independent sourcing model means that Yeşil Grup Enerji does not represent Siemens as an official distributor or manufacturer-appointed representative.

Instead, procurement activities are carried out independently according to the customer's technical specification, project requirements and sourcing needs.

For SITRANS P320 MLFB inquiries, Siemens P320 replacement projects, P DS III/P410 modernization or project-specific technical configuration verification, providing the existing transmitter's complete MLFB or technical specification can significantly improve the accuracy of the sourcing process.


Conclusion

The Siemens SITRANS P320 is a modern digital pressure transmitter combining high measurement performance, digital communication, advanced diagnostics and functional safety capabilities for demanding industrial applications.

With up to 0.065% accuracy, measuring ranges from 10 mbar to 700 bar depending on configuration, HART, PROFIBUS PA and FOUNDATION Fieldbus communication options, NAMUR NE107 diagnostics, Remote Safety Handling and support for SIL 2/3 applications, the P320 is a strong option for both critical process applications and modernization projects.

However, selecting the correct P320 requires more than specifying the product family. The complete MLFB, measuring cell, pressure range, process connection, materials, communication protocol, certifications and safety requirements should all be evaluated together.

For older SITRANS P DS III and P410 installations, P320/P420 can provide successor/replacement options for applicable configurations. The correct replacement should nevertheless be determined through a configuration-based technical cross-reference rather than a simple product-name substitution.

Yeşil Grup Enerji is not an official Siemens distributor or authorized representative. As an independent and brand-independent industrial sourcing supplier, Yeşil Grup Enerji can support Siemens SITRANS P320 projects through global sourcing, MLFB verification, replacement analysis, technical configuration review and project-based RFQ processes.

Contact Form