The Siemens SITRANS P DS II is a legacy pressure transmitter family used in industrial applications requiring gauge pressure, absolute pressure and differential pressure measurement. Depending on the configuration, these transmitters may also be used in flow and level measurement applications.
For facilities operating with existing DS II instruments, identifying a suitable replacement involves more than selecting a transmitter with a similar measuring range. The complete order number, process connection, measuring cell, output signal, communication protocol, pressure rating, wetted materials and installation requirements must be evaluated.
As legacy instrumentation reaches the end of its product lifecycle, maintenance teams and procurement departments may need to identify technically suitable alternatives while minimizing modifications to existing process installations.
The lifecycle status of a SITRANS P DS II transmitter should be verified against the complete MLFB (Machine-Readable Product Designation) and the relevant Siemens product documentation.
The lifecycle status of a product family should not automatically be applied to every configuration within that family. Different order numbers may have different availability, documentation and successor-product information.
Before initiating a replacement project, verify:
The complete MLFB and the exact transmitter configuration.
Whether the specific product is active, discontinued or classified as a legacy product.
Whether Siemens identifies a successor for that exact product record.
Whether the original measuring range and process connections can be retained.
Whether the replacement requires changes to wiring, configuration, mounting or commissioning procedures.
Important: A successor listed for a particular SITRANS P DS III or P410 configuration does not automatically constitute a direct replacement for every SITRANS P DS II model. The final selection requires model-specific technical evaluation.
SITRANS P DS II transmitters were available in different configurations for industrial pressure measurement. The actual technical characteristics depend on the specific model, measuring cell and ordering options.
Relevant parameters include:
Measurement type: Gauge pressure, absolute pressure or differential pressure, depending on the configuration.
Measuring range: Determined by the installed measuring cell and the selected order code.
Output and communication: Must be verified against the original instrument's electrical and communication configuration.
Process connection: Threaded, flanged or other connection arrangements, depending on the model.
Wetted materials: Must be checked for compatibility with the process medium and operating conditions.
Pressure and temperature limits: Must be evaluated against the specific transmitter configuration.
Installation requirements: Mounting dimensions, impulse lines, manifolds and process interfaces may affect replacement suitability.
Not every DS II transmitter has the same housing material, diaphragm construction, output signal or communication protocol. These details should be confirmed using the original nameplate, complete MLFB and applicable technical documentation.
The MLFB is essential when identifying an existing SITRANS P DS II transmitter or evaluating a replacement.
A family name alone does not provide sufficient information to establish the exact technical configuration. Similar-looking instruments may differ in measuring range, process connection, output, materials, approvals or other ordering options.
For reliable identification, collect the following information:
| Identification item | Why it matters |
|---|---|
| Complete MLFB | Identifies the specific ordered configuration |
| Nameplate information | Helps confirm the model and product identity |
| Measurement type | Establishes whether gauge, absolute or differential pressure is required |
| Measuring range | Ensures the replacement covers the required operating range |
| Process connection | Helps maintain mechanical compatibility |
| Output and protocol | Supports electrical and control-system compatibility |
| Wetted materials | Helps establish process-medium compatibility |
| Approvals and certifications | Confirms suitability for the installation environment |
| Existing accessories | Identifies relevant manifolds, seals, mounting parts and interfaces |
If the complete MLFB is unavailable, photographs of the nameplate, process connection and installation can help with preliminary identification. Final selection should still be based on verified technical information.
The following table summarizes the principal parameters to review when assessing a legacy SITRANS P DS II instrument.
| Parameter | Technical assessment |
|---|---|
| Measurement type | Gauge, absolute or differential pressure, depending on the model |
| Measuring range | Must be confirmed against the complete MLFB |
| Output signal | Verify the original electrical output and available options |
| Communication | Confirm compatibility with the installed control and instrumentation system |
| Process connection | Check thread/flange type, dimensions and pressure rating |
| Wetted materials | Verify compatibility with the process medium |
| Process temperature | Confirm the limits for the exact configuration |
| Overpressure limits | Check the relevant measuring cell and product documentation |
| Hazardous-area approvals | Verify the specific certificates and ordering options |
| Enclosure protection | Confirm the protection rating for the selected model |
| Mounting arrangement | Check dimensions and installation interfaces |
These parameters must not be assumed to be identical across the entire DS II family. Where documentation is incomplete, the instrument should be assessed using the available nameplate data, original specifications and process requirements.
Depending on the installed configuration, legacy SITRANS P DS II transmitters may be encountered in a range of industrial measurement applications.
Gauge and absolute pressure configurations can be used to monitor operating pressure in industrial equipment and process lines. Replacement selection should consider the normal operating range, expected pressure fluctuations and permissible overpressure.
Differential pressure configurations can be used to measure the pressure difference between two process points. The application may require specific manifolds, impulse lines, isolation arrangements or remote seals.
Differential pressure transmitters may be used in flow measurement systems with suitable primary elements, such as orifice plates. The replacement assessment should include the primary element, pressure connections and any square-root extraction performed by the transmitter or control system.
Differential pressure-based level applications require consideration of liquid density, tank pressure, vessel geometry and the arrangement of impulse lines. Wet-leg, dry-leg and remote-seal configurations may affect the required replacement design.
In every application, the replacement must be selected based on the measurement principle and complete process configuration—not solely on the transmitter's nominal pressure range.
The Siemens SITRANS P320 and P420 product families may be relevant candidates when evaluating replacements for certain legacy pressure transmitters. However, suitability depends on the original instrument and the application requirements.
The SITRANS P320 is a smart pressure transmitter family intended for industrial pressure measurement. Depending on the configuration, the range includes options for gauge pressure, absolute pressure, differential pressure, flow and level applications.
Potential selection considerations include:
Required measuring range and measuring cell.
Measurement type and process connection.
Available communication and output options.
Functional safety requirements and the applicable product configuration.
Process temperature, pressure rating and wetted materials.
Mounting and commissioning requirements.
The SITRANS P420 is another candidate for evaluating selected legacy pressure measurement installations. As with the P320, the exact model and configuration must be selected according to the process requirements.
The P420 should not be treated as a universal replacement for every DS II transmitter. The complete ordering code, application, process interfaces, required approvals and control-system requirements must be reviewed before a replacement decision is made.
The SITRANS P410 belongs to an earlier generation of Siemens pressure transmitters, and some configurations have been discontinued. It should not automatically be presented as a current replacement option.
Siemens product records identify the P320/P420 as successors for certain discontinued SITRANS P DS III/P410 configurations. That information is relevant to those specific product records, but it does not establish a universal, one-to-one replacement mapping for SITRANS P DS II.
The P500 should likewise not be assumed to be a routine replacement. Its suitability must be assessed against the specific application, configuration and current product documentation.
Replacement principle: Treat the P320 and P420 as candidates for technical evaluation—not as automatic substitutes for every DS II model.
The following table is intended as an initial screening guide. It is not an official Siemens cross-reference table and does not establish direct model-to-model equivalence.
| Existing application or requirement | Candidate for evaluation | Checks required before selection |
|---|---|---|
| Gauge pressure measurement | SITRANS P320 or P420, where suitable | Measuring range, process connection, output and approvals |
| Absolute pressure measurement | SITRANS P320 or P420, where suitable | Absolute-pressure measuring cell, range and process interfaces |
| Differential pressure measurement | Suitable P320/P420 differential pressure configuration | Differential range, static pressure, manifolds and impulse lines |
| Flow measurement using differential pressure | Suitable differential pressure configuration | Primary element, flow calculation, square-root extraction and process conditions |
| Differential pressure-based level measurement | Suitable level or differential pressure configuration | Liquid density, tank pressure, wet/dry legs and remote seals |
| Installation with special materials or process connections | Configuration selected after technical review | Wetted materials, seals, connection dimensions and temperature limits |
| Installation requiring hazardous-area approval | Approved configuration appropriate to the installation | Exact certificate, protection concept and applicable regulations |
A technically suitable replacement may require changes to mounting, process connections, wiring, configuration or commissioning. These changes should be identified before the purchase decision.
Before replacing a SITRANS P DS II transmitter, review the following items:
Identify the original instrument. Record the full MLFB and nameplate details.
Confirm the measurement task. Determine whether the application measures gauge pressure, absolute pressure, differential pressure, flow or level.
Review the operating conditions. Record normal and maximum pressure, process temperature and expected fluctuations.
Check the process interface. Verify connections, seals, manifolds, impulse lines and wetted materials.
Confirm electrical compatibility. Review supply requirements, output signals, wiring and communication protocol.
Check the control-system configuration. Assess scaling, engineering units, damping, alarms and other relevant parameters.
Verify approvals. Confirm hazardous-area and functional-safety requirements where applicable.
Review mechanical installation. Compare mounting dimensions and access requirements.
Confirm lifecycle and availability. Verify the current status of the proposed product and its ordering code.
Document any deviations. Identify changes required for installation, commissioning and maintenance.
The final replacement decision should be based on the complete application—not only on a similar model name or nominal measuring range.
Even when a replacement transmitter has a compatible measurement range, installation and commissioning requirements may differ.
Before commissioning, verify:
The transmitter's configured measuring range and engineering units.
The correct high- and low-pressure connections for differential pressure applications.
Manifold and impulse-line arrangements.
Electrical wiring, supply voltage and signal configuration.
Control-system scaling and any square-root extraction.
Alarm settings, damping and relevant process parameters.
The instrument's response under operating conditions.
Required calibration, loop checks and documentation.
For safety-related applications, the selected transmitter and the complete safety instrumented function must be assessed against the applicable safety requirements. A product's general capabilities should not be interpreted as blanket confirmation of suitability for every SIL application.
Commissioning should follow the applicable manufacturer documentation, site procedures and relevant safety requirements.
When a legacy transmitter shows abnormal readings or communication problems, the issue should be investigated systematically before deciding whether replacement is necessary.
| Symptom | Possible causes | Recommended checks |
|---|---|---|
| No output signal | Power supply, wiring or instrument fault | Verify supply, wiring polarity and loop continuity |
| Unstable readings | Process fluctuations, impulse-line problems or configuration issues | Check process conditions, impulse lines, connections and damping |
| Incorrect measurement | Incorrect range, scaling, zero point or installation | Verify the configured range, engineering units and installation |
| Differential pressure offset | Unequal pressure connections, blocked impulse lines or incorrect zeroing conditions | Inspect both pressure paths and follow the applicable zero-check procedure |
| Communication problems | Wiring, configuration or protocol incompatibility | Verify the communication setup and control-system interface |
| Repeated maintenance issues | Ageing equipment, environmental conditions or process compatibility | Review service history, installation conditions and replacement feasibility |
These symptoms do not prove that the transmitter has reached the end of its service life. A proper diagnosis should distinguish instrument failure from process, wiring, installation and configuration problems.
Where the instrument is obsolete or repair is no longer practical, a replacement assessment can help establish a technically appropriate path forward.
Sourcing a legacy industrial transmitter can require more than locating a product with a similar description. The exact ordering code, technical configuration, product lifecycle and documentation must be checked to reduce procurement risk.
Yeşil Grup Enerji supports industrial instrumentation procurement through an independent, brand-independent sourcing approach. Depending on the project, support may include:
MLFB and product-code verification.
Datasheet and configuration review.
Technical suitability assessment.
Replacement and cross-reference analysis.
Review of alternative sourcing channels.
Project-specific RFQ coordination.
Quotation support based on the confirmed product and project requirements.
Product availability, lifecycle status, lead time and commercial terms must be confirmed for each specific inquiry. A proposed alternative should be technically reviewed before it is treated as equivalent to the original instrument.
To support an accurate quotation and technical assessment, include as much of the following information as possible:
Manufacturer and complete model designation.
Full MLFB or ordering code.
Nameplate photographs, if available.
Required quantity.
Measurement type and measuring range.
Process connection and wetted-material requirements.
Output signal and communication protocol.
Operating pressure and process temperature.
Required approvals or certifications.
Installation or application details.
Delivery destination and required delivery schedule.
Any replacement constraints, such as maintaining existing connections or control-system interfaces.
If the original MLFB is incomplete or unavailable, provide the nameplate, installation photographs and existing datasheet where possible. These details can help establish the configuration, although the final selection remains subject to technical verification.
Availability and lifecycle status depend on the specific product configuration. The complete MLFB should be checked against current manufacturer documentation and relevant sourcing channels.
The P320 may be a candidate for certain applications, but it should not be considered an automatic replacement for every DS II model. The measurement type, range, process connection, output, materials, approvals and installation requirements must be compared.
No universal one-to-one replacement should be assumed. Suitability depends on the original configuration and the process requirements. The complete MLFB and relevant technical documentation should be reviewed before selection.
Some P410 configurations have been discontinued. The lifecycle status must be checked for the exact order code, and a proposed alternative should be assessed against the original application's requirements.
The complete MLFB is the most useful starting point. The nameplate, measuring range, process connection, output signal, communication protocol and application details also help establish the configuration.
Not necessarily. Mechanical dimensions, process connections, wiring, communication, configuration and commissioning requirements may differ. These factors should be reviewed before finalizing the replacement.
No. Yeşil Grup Enerji is not Siemens' official distributor or authorized representative. The company operates as an independent, brand-independent industrial supplier and supports product identification, technical evaluation, replacement analysis and project-specific sourcing.
The Siemens SITRANS P DS II is a legacy pressure transmitter family for which replacement decisions should be based on the exact product configuration and the requirements of the installed process.
The SITRANS P320 and P420 may be relevant candidates for selected applications, but neither should be treated as a universal, direct replacement for every DS II model. Complete MLFB verification, lifecycle review, process compatibility checks and technical comparison are essential steps in selecting an appropriate alternative.
Yeşil Grup Enerji is not Siemens' official distributor or authorized representative. As an independent, brand-independent industrial spare parts supplier, Yeşil Grup Enerji supports MLFB verification, datasheet and configuration review, technical suitability assessment, replacement/cross-reference analysis, global sourcing and project-specific RFQ coordination.
For technical review and project-specific quotation support, contact:
Website: https://yesilgrupenerji.com
Email: [email protected]
Phone: +90 505 696 61 00
Share the complete MLFB, nameplate details and application requirements to help initiate a technically informed assessment.