- Automation & ControlView all 1,798 products
- AC Drives
- Industrial Communications
- PLC & I/O Cards
- Vibration Monitoring
- Automation Accessories
- Controllers & Data Acquisition
- CCTV & Security
- Safety Switches & Guard Locking
- Isolator & Barrier
- Encoders
- HMI Displays
- Industrial Computers
- Servo Drives
- Motor Soft Starters
- Pneumatic Cylinders
- Automation Software
- Machine Vision
- Robotics
Brand: Endress+Hauser (E & H)
Endress+Hauser PMP55 Cerabar M Diaphragm Seal Transmitter
Description
Endress+Hauser PMP55 Cerabar M diaphragm seal pressure transmitter
The Endress+Hauser PMP55 is the diaphragm seal version of the Cerabar M process pressure transmitter. Instead of exposing the sensor directly to the process, the PMP55 hides a silicon measuring cell behind a welded, oil-filled diaphragm seal, so the transmitter can be used with very hot or very cold media, aggressive fluids, sticky or crystallising products and hygienic lines. The measuring cell is the same piezoresistive metallic-membrane cell that is used in the PMP51; the seal is what makes the PMP55 different. Seven Star LLC supplies the PMP55 in Oman and the GCC as an independent supplier based in Muscat.
In the Cerabar M family the PMC51 uses a ceramic membrane, the PMP51 a direct metallic membrane and the PMP55 a metallic membrane behind a diaphragm seal. The PMP55 covers measuring cells from 400 mbar up to 400 bar and, depending on the seal and fill fluid, process temperatures from –70 °C up to +400 °C.
PMP55 technical specifications
| Parameter | Specification |
|---|---|
| Manufacturer / part number | Endress+Hauser PMP55 (Cerabar M, diaphragm seal version) |
| Measuring principle | Piezoresistive silicon cell with metallic process membrane, pressure transferred through a diaphragm seal and fill fluid |
| Measured variable | Absolute pressure or gauge pressure; level, volume or mass derived from pressure (HART, PROFIBUS PA, FOUNDATION Fieldbus) |
| Measuring cells (gauge and absolute) | 400 mbar, 1, 2, 4, 10, 40, 100 and 400 bar (6 psi to 6 000 psi) |
| Maximum working pressure / overpressure limit | Up to 400 bar (6 000 psi) MWP; overpressure limit up to 600 bar (9 000 psi) on the 400 bar cell, depending on the lowest-rated component |
| Minimum upper range value (absolute) | 80 mbar abs (1.16 psi abs) must be observed within the measuring range |
| Reference accuracy | Standard up to ±0.15 %; Platinum up to ±0.075 % (Platinum only with direct diaphragm seal mounting, not on the 400 mbar cell) |
| Turn down | Up to 20:1 set at the factory, higher values can be configured on the device |
| Process temperature | –70 to +400 °C (–94 to +752 °F) depending on seal and fill fluid; tantalum membrane –70 to +300 °C |
| Ambient temperature | –40 to +85 °C without display; –20 to +70 °C with LCD (extended range with limited display performance) |
| Output | 4 to 20 mA; 4 to 20 mA with HART 6.0; 4 to 20 mA with IO-Link; PROFIBUS PA; FOUNDATION Fieldbus |
| Supply voltage | 11.5 to 45 V DC for 4 to 20 mA and HART (11.5 to 30 V DC for intrinsically safe versions); 18 to 30 V DC when IO-Link is used |
| Functional safety | Process pressure monitoring up to SIL 2 (IEC 61508 and IEC 61511), assessed by TUeV NORD |
| Membrane materials | Selected with the diaphragm seal, for example 316L, Alloy C, Monel, tantalum, PTFE-coated or gold-rhodium coated |
Figures are from the Endress+Hauser Technical Information for the Cerabar M PMC51, PMP51 and PMP55; the lowest-rated element of the ordered system always applies.
How the PMP55 measures through a diaphragm seal
The process pressure acts on the membrane of the diaphragm seal. A fill fluid in the seal and, where fitted, in the capillary transfers that pressure to the membrane of the measuring cell, where a Wheatstone resistance bridge converts the deflection into a voltage that the electronics evaluate. Endress+Hauser delivers the seal systems welded and hermetically sealed, so there are no threaded joints that can leak oil.
Three design choices set the behaviour of the system: the diameter and stiffness of the seal membrane, the fill fluid, and the capillary or temperature isolator between seal and cell. A larger and softer membrane produces less temperature error. The TempC process membrane, available on selected seals, is designed to reduce the effect of ambient and process temperature swings and works from –70 °C to +400 °C, which suits long steam-in-place and cleaning cycles. Overload resistance is guaranteed at four times the cell’s nominal pressure.
PMP55 fill fluids and temperature limits
The fill fluid decides how hot, how cold and how deep a vacuum the seal system can handle. The table lists the permitted ranges from the datasheet; the device and seal limits still apply on top.
| Fill fluid (PMP55 order option) | At 0.05 bar abs | At 1 bar abs or more |
|---|---|---|
| Silicone oil, food suitable (1) | –40 to +180 °C | –40 to +250 °C |
| Inert oil (2) | –40 to +100 °C | –40 to +175 °C (150 °C continuous, 175 °C up to 200 h) |
| Vegetable oil, food suitable (4) | –10 to +160 °C | –10 to +220 °C |
| High-temperature oil (5) | –20 to +200 °C | –20 to +400 °C (400 °C limited to 10 h, 350 °C to 200 h) |
| Low-temperature oil (6) | –70 to +120 °C | –70 to +180 °C |
The range of a complete PMP55 system also depends on capillary length and diameter, and is calculated with the manufacturer’s sizing tool; send us the process conditions for confirmation.
Where the PMP55 fits in the Cerabar M platform
The Cerabar M platform shares one electronics and operating concept with the Deltabar M differential pressure and Deltapilot M hydrostatic level transmitters, so spare plug-in electronics and menu structure are familiar across the range. Within the pressure line the sibling parts are the PMC51, the PMP51 and the PMP55 described here. If the medium is clean and below about 130 °C a PMP51 is simpler; the PMP55 earns its place when the seal solves a real problem. A mounting bracket is recommended near hot lines, and a capillary is recommended under vibration because it decouples the electronics from the pipe. The housing is aluminium F31 or stainless steel F15 (hygienic).
| Model | Membrane | Typical use |
|---|---|---|
| PMC51 | Ceramic (Ceraphire), gauge or absolute | Clean or abrasive media, vacuum, up to 40 bar |
| PMP51 | Direct metallic membrane, threaded or flush | General process, up to 400 bar |
| PMP55 | Metallic membrane behind diaphragm seal, optional capillary | Extreme temperatures, aggressive or sticky media, hygienic lines |
PMP55 selection and ordering checklist
- Sensor range: choose the cell with the lowest span that still covers the maximum pressure; order codes run from 1F (400 mbar gauge) to 1W (400 bar gauge) and from 2F to 2W for absolute.
- Output: 4 to 20 mA (1), 4 to 20 mA HART (2), PROFIBUS PA (3), FOUNDATION Fieldbus (4) or 4 to 20 mA with IO-Link (7).
- Diaphragm seal: process connection type, nominal size, membrane material and coating; hygienic and flanged designs are both available.
- Fill fluid and temperature: pick the oil that fits the highest and lowest process temperature and the vacuum condition.
- Capillary: direct mounting, temperature isolator or capillary in metres or feet, with 316L, PVC-coated or PTFE-jacketed armour.
- Hazardous area and housing: state the required Ex protection, housing material and cable entry.
- Services: oxygen cleaning and material certificates are selectable.
PMP55 installation, commissioning and maintenance
Support the capillary along its whole length and never bend it tighter than the stated radius; an unsupported capillary causes zero shifts and fatigue. Where two seals are used for electrical differential pressure, keep both capillaries under similar ambient conditions. Keep the transmitter head out of radiated heat and use a bracket on hot lines.
After installation, check the zero with the process isolated and vented. If the TempC membrane overshoots after a temperature shock, add damping (0 to 999 seconds, factory value 2 seconds). The electronics are ready five seconds after power-up, and the 4 to 20 mA loop can be tested through the test terminals without interrupting the measurement. Never clean a seal membrane with a sharp tool; flush it using the plant procedure. Long-term stability is 0.15 % of the upper range limit per year for the metallic cells.
Typical PMP55 applications in Oman and the GCC
In Oman and the GCC a diaphragm seal transmitter such as the PMP55 is chosen for viscous crude and bitumen lines, sour or chlorinated process streams, hot oil and heat transfer systems, steam-traced lines, polymer and resin plants, sulphur and slurry service, and sanitary connections in dairy, beverage and pharmaceutical production. Long capillaries suit tall columns where the transmitter is read at ground level. On coastal sites choose the housing and coating specified for corrosive atmospheres, and in desert plants shade the display and seal cable glands against dust.
Information to send with a PMP55 RFQ
- Part number PMP55 and, if replacing a unit, the complete order code from the nameplate.
- Pressure range, maximum pressure, and whether vacuum can occur.
- Process medium, minimum and maximum temperature, and cleaning or sterilisation cycles.
- Process connection (flange standard, size and rating, or hygienic connection) and seal membrane material.
- Capillary length and armour, or direct mounting, plus ambient conditions.
- Output, Ex approval, housing, cable entry, certificates and quantity.
Documents and quotation
The Endress+Hauser Technical Information for the Cerabar M PMC51, PMP51 and PMP55 is attached on this page, with the measuring ranges, fill fluid data and ordering structure.
Send us the PMP55 details above and Seven Star LLC will prepare a quotation for Oman and the GCC.
Other Models in the Eh Cerabar Pmp Pmc Range
Seven Star LLC supplies models from the Eh Cerabar Pmp Pmc range in Oman and the GCC. Compare the related models below and request a quote for the one that matches your application.
| Model | Category | |
|---|---|---|
| Endress+Hauser PMP11 Cerabar Pressure Transducer | Pressure Instrumentation | View details |
| Endress+Hauser PMC11 Cerabar Ceramic Pressure Transducer | Pressure Instrumentation | View details |
| Endress+Hauser PMP21 Cerabar Metal Pressure Transducer | Pressure Instrumentation | View details |
| Endress+Hauser PMC21 Cerabar Ceramic Pressure Transducer | Pressure Instrumentation | View details |
| Endress+Hauser PMP23 Cerabar Hygienic Pressure Transducer | Pressure Instrumentation | View details |
| Endress+Hauser PMP55 Cerabar M Diaphragm Seal Transmitter | Pressure Instrumentation | You are viewing this model |
Datasheets & Documents
- Datasheet Endress+Hauser PMP55 Technical Information (Cerabar M) Download
Reviews (0)
About brand
Endress+Hauser makes process measurement instruments for flow, level, pressure, temperature and liquid analysis. Georg H. Endress and Ludwig Hauser started the business in Lörrach, Germany, on 1 February 1953, first selling level meters, and the Endress+Hauser name has been used since 1957. The group is headquartered in Reinach, Switzerland, and has been wholly owned by the Endress family since 1975.
Seven Star LLC is an independent supplier listing Endress+Hauser flowmeters, level and pressure transmitters, temperature assemblies and liquid analysis products for buyers in Oman and the GCC. Instruments are matched from the full order code on the nameplate.
Endress+Hauser company profile
| Origin | Founded in Lörrach, Germany, on 1 February 1953 by the Swiss engineer Georg H. Endress and Ludwig Hauser |
|---|---|
| Headquarters | Endress+Hauser AG, Reinach (Basel-Landschaft), Switzerland |
| Ownership | Family owned; the Endress family has been the sole shareholder since 1975, and a family charter commits the company to stay family owned |
| Size | About 16,500 employees and sales of about EUR 3.7 billion (2023, as reported by the company) |
| Product families | Proline flowmeters, Micropilot and Levelflex radar, Liquiphant switches, Cerabar and Deltabar pressure, iTEMP and iTHERM temperature, Liquiline and Memosens liquid analysis |
Milestones
- 1953: Georg H. Endress and Ludwig Hauser start the business in Lörrach on 1 February, first selling level meters.
- 1957: The Endress+Hauser name comes into use.
- 1975: The Endress family becomes sole shareholder.
- 2023: About 16,500 employees and sales of about EUR 3.7 billion, as reported by the company.
Endress+Hauser product lines
| Line | Measuring principle | Typical use |
|---|---|---|
| Promass F 300, Promass 80F, 83F/84F | Coriolis mass flow | Direct mass flow and density of liquids and gases, hydrocarbon transfer and chemical dosing |
| Promag P 300, P 500, H 300, W 400, W 10, 50P | Electromagnetic flow | Water, wastewater, slurries and other conductive liquids |
| Prowirl F 200, 72F | Vortex flow | Steam, gas and low-viscosity liquids |
| Prosonic Flow 92F, t-mass 65F | Ultrasonic and thermal mass flow | Water lines; compressed air and industrial gases |
| Micropilot FMR62, FMR67, FMR60, FMR10B, FMR20, FMR50, FMR52 | Free-space radar level, 80 GHz and 26 GHz | Tanks, process vessels, silos and open water channels |
| Levelflex FMP51, FMP50, FMP54, FMP55 | Guided wave radar level | Level and interface in vessels, separators and bypass chambers |
| Liquiphant FTL51, Prosonic S FMU90 | Vibronic point level; ultrasonic level | High and low level alarms, pump protection, open channel flow |
| Cerabar PMC71B, PMP51B, PMP71, Deltabar PMD78B, PMD75 | Pressure and differential pressure | Process pressure, hydrostatic level and DP flow |
| iTEMP TMT82, TMT162, iTHERM TM101, TR66, TR10 | Temperature transmitters and thermometers | RTD and thermocouple points with thermowells |
| Liquiline CM444, CM442, Memosens CPS11E, Stamolys reagents | Liquid analysis | pH, ORP, conductivity, dissolved oxygen and nutrient analysis in water treatment and process |
Where Endress+Hauser instruments are used
In Oman and the GCC, Endress+Hauser instruments are common in oil and gas production and processing, refineries and petrochemicals, desalination and water networks, wastewater treatment, power plants and food and beverage plants. Coriolis meters measure hydrocarbon and chemical flows, electromagnetic meters cover water and wastewater, radar transmitters handle tank and silo level, and Liquiline analysers monitor water quality. Proline 300 and 500 flowmeters include Heartbeat Technology for in-situ verification, which reduces the need to remove a meter for checks.
Ordering Endress+Hauser instruments: what we need
The order code on the nameplate (for example PMP71-1QA1S11RDADU) defines every option: measuring range, process connection, materials, output, approvals and display. Send it with the serial number; Endress+Hauser can retrieve the original configuration from the serial number. For a new instrument add the medium, operating and design pressure and temperature, range, line size or tank geometry, process connection, wetted materials, output or protocol (4-20 mA HART, PROFIBUS, FOUNDATION Fieldbus, Modbus) and the hazardous-area approval required. Older models such as Promass 80/83 or Micropilot M are replaced by current Proline or 80 GHz Micropilot devices.
Facts checked against Endress+Hauser company history and product information, October 2026.
Browse Endress+Hauser products by category: Flowmeters, Level Transmitter, Pressure Instrumentation, Temperature, Liquid Analysis Sensors, Liquid Analytical Systems.
FAQ
Questions about the Endress+Hauser PMP55 Cerabar M Diaphragm Seal
Answers from our engineering team on installation, compatibility and integration.
01What is the difference between the PMP51 and the PMP55?
Both use the same silicon cell with metallic membrane. The PMP51 has the membrane directly at the process connection, while the PMP55 adds a welded diaphragm seal with fill fluid and, optionally, a capillary. The seal extends the temperature range and protects the cell from aggressive or sticky media.
02What process temperature can the PMP55 handle?
Depending on the diaphragm seal and fill fluid, the datasheet gives –70 to +400 °C. Tantalum membranes are limited to –70 to +300 °C. The permitted range of a complete system also depends on the capillary and must be checked against the fill fluid limits.
03Which output options does the PMP55 offer?
4 to 20 mA analog, 4 to 20 mA with HART 6.0, 4 to 20 mA with IO-Link, PROFIBUS PA and FOUNDATION Fieldbus. The 4 to 20 mA and HART versions run on 11.5 to 45 V DC, or 11.5 to 30 V DC in intrinsically safe versions.
04Can the PMP55 be used in safety instrumented functions?
The datasheet states that the Cerabar M can be used for process pressure monitoring up to SIL 2, assessed to IEC 61508 and IEC 61511. The functional safety manual and the actual order code must be checked for each application.
05What accuracy can I expect from a PMP55?
Standard reference accuracy is up to ±0.15 % and the Platinum version up to ±0.075 %, the latter only with direct diaphragm seal mounting. Total error also includes temperature effects of the seal system, which grow with capillary length and process temperature swings.
Reviews
There are no reviews yet.