Vapour Pressure Monitoring
Vapour pressure is one of the most critical thermodynamic properties in chemical and petrochemical processing. Every volatile liquid, solvent, intermediate, monomer, and finished product exerts a characteristic vapour pressure that varies with temperature, composition, and the presence of dissolved gases or light-end impurities. Accurate, continuous vapour pressure monitoring governs safe storage and handling (ensuring vessels and pipework remain below the maximum allowable working pressure as ambient or process temperatures rise), product quality assurance (confirming that Reid vapour pressure, true vapour pressure, or bubble point specifications are met before dispatch), distillation and fractionation control (tracking vapour-liquid equilibrium conditions across column internals), reactor safety (detecting vapour pressure buildup from exothermic reaction, solvent boil-off, or thermal decomposition), and environmental compliance (minimising fugitive VOC emissions from tank breathing, loading operations, and process vents by maintaining vapour space pressure within controlled limits).
Loss of vapour pressure control is a precursor to many of the most serious incidents in the chemical industry. Undetected vapour pressure rise in storage tanks leads to relief valve lifting and uncontrolled atmospheric releases. Excessive vapour pressure in transfer lines causes cavitation, pump seal failure, and loss of containment. Vapour pressure exceedances in reactor vessels indicate runaway conditions requiring emergency intervention. Inadequate vapour pressure monitoring during blending operations allows off-specification product to enter the supply chain, with downstream safety and performance consequences.
At Stork Solutions, we supply a comprehensive range of ATEX/IECEx-certified pressure transmitters for vapour space monitoring, ceramic sensor transmitters for corrosive vapour environments, flush-diaphragm transmitters for condensing and fouling vapour service, differential pressure transmitters for vapour-liquid equilibrium and column delta-P, electronic pressure switches for vapour pressure alarm and interlock, dual-output pressure and temperature transmitters for correlated vapour pressure-temperature verification, IO-Link smart transmitters, PID controllers, and multichannel data loggers engineered for vapour pressure monitoring across storage, processing, transfer, and distribution operations.
Product Spotlight for Vapour Pressure Monitoring
Why Vapour Pressure Demands Dedicated Instrumentation
Vapour pressure measurement presents a distinct set of challenges that differentiate it from general process pressure monitoring:
Temperature dependence – vapour pressure is exponentially related to temperature (Clausius-Clapeyron relationship); small temperature changes produce large vapour pressure changes, particularly near the boiling point; instruments must respond quickly to pressure changes driven by thermal transients and provide correlated pressure-temperature data for meaningful vapour pressure assessment
Low absolute pressures – many vapour space monitoring applications operate at or near atmospheric pressure, in the range from tens of millibar to a few hundred millibar gauge; transmitters must deliver high resolution, excellent linearity, and minimal thermal drift at these low pressures where measurement errors have the greatest process impact
Condensation and wetting – vapour spaces in storage tanks, columns, condensers, and vent headers contain saturated or near-saturated vapours that condense on cooler surfaces including pressure sensor diaphragms and impulse tubing; condensate accumulation causes measurement error, impulse line blockage, and corrosive attack on sensor materials; flush-diaphragm and self-draining mounting configurations are essential
Corrosive vapour environments – chemical vapour spaces routinely contain acidic vapours (HCl, SO2, NO2, acetic acid, formic acid), caustic mists, chlorinated solvent vapours, amine vapours, and other chemically aggressive atmospheres that corrode conventional stainless steel sensors; ceramic and PVDF wetted materials provide the durability needed for sustained service in corrosive vapour environments
Flammable and toxic vapour atmospheres – vapour spaces above flammable liquids are classified ATEX Zone 0 (inside the vessel) and Zone 1 (immediately adjacent); all pressure instrumentation must carry appropriate ATEX/IECEx certification for the zone of installation
Multi-component vapour systems – real chemical processes involve multi-component mixtures where vapour pressure depends on composition as well as temperature; monitoring vapour pressure during blending, distillation, stripping, and reaction tracks composition changes in real time
Regulatory and environmental pressure – EPA, Environment Agency (UK), SEPA, IED, and local air quality regulations require facilities to monitor and control VOC emissions from storage tanks, loading operations, and process vents; vapour space pressure monitoring is a key element of tank breathing loss control, vapour recovery system performance verification, and emissions inventory compliance
Dynamic conditions – vapour pressure in process vessels changes continuously with temperature cycling (day/night, seasonal), batch additions, reaction progress, feed composition variations, and operational mode changes (filling, emptying, circulating, heating, cooling); transmitters must track these dynamic changes accurately without lag or overshoot
Vapour Space Pressure Monitoring on Storage Tanks and Process Vessels
The primary measurement: continuous pressure monitoring in the vapour space above stored or processed liquids to track vapour pressure behaviour, detect abnormal pressure buildup, confirm vent and breathing valve performance, and provide the data foundation for safe storage management and environmental compliance:
DMP 331 Industrial Pressure Transmitter for Low Pressure – 100 mbar to 60 bar | Piezoresistive stainless steel sensor | 4-20 mA / 0-10 V | ATEX Ex ia | SIL 2 | The general-purpose ATEX transmitter for vapour space pressure monitoring across storage tanks, day tanks, blending vessels, reactor head spaces, and process drums; SIL 2 certification supports high-pressure trip and emergency vent activation through the plant SIS when vapour pressure exceeds the safe operating envelope; proven long-term stability maintains measurement accuracy across extended storage campaigns and seasonal temperature cycling
DMP 343 Industrial Pressure Transmitter – 10 mbar to 1,000 mbar | Excellent linearity | Minimal thermal effect | Superior long-term stability | ATEX Ex ia | The primary transmitter for low-pressure vapour space monitoring on atmospheric and low-pressure storage tanks where vapour pressure operates in the millibar range; 10 mbar low-end capability provides the resolution needed to detect subtle vapour pressure changes from temperature variation, composition drift, dissolved gas evolution, and light-end accumulation; excellent linearity and minimal thermal effect ensure accurate measurement at the low absolute pressures where tank breathing losses, conservation vent set-point margins, and vapour recovery system performance are assessed
DMP 331 P Industrial Pressure Transmitter – 100 mbar to 40 bar | Flush diaphragm | CIP/SIP 150 degrees C | Vacuum resistant | IS Ex ia | SIL 2 | Optional Hastelloy or Tantalum diaphragm | Cooling element to 300 degrees C | For vapour space monitoring where condensing vapours, mist carryover, polymer deposits, sublimation products, or particulate entrainment would block conventional impulse tubing and threaded pressure ports; Hastelloy and Tantalum diaphragm options provide long-term resistance to corrosive condensates forming on the sensor face in acidic, caustic, or halogenated vapour environments; cooling element enables direct mounting on hot vessel nozzles where elevated vapour temperatures would damage conventional electronics
DMP 331 P i Precision Pressure Transmitter – 400 mbar to 40 bar | 16-bit digital signal processing | Turn-down 1:10 | 0.04% FSO/10K temperature response | For precision vapour pressure measurement where tight temperature coefficient performance maintains accuracy across the significant ambient and process temperature variations that drive vapour pressure changes; essential for product quality applications where vapour pressure must be determined to tight tolerances for specification compliance and custody transfer documentation
DMP 335 Industrial Pressure Transmitter – 10 bar to 600 bar | Welded stainless steel sensor (no fill fluid, no elastomeric seals) | ATEX Ex ia | Suitable for oxygen applications | Insensitive to pressure peaks | For vapour pressure monitoring on pressurised storage vessels, LPG and liquefied gas spheres, pressurised rail cars, and ISO containers where the vapour pressure of the stored product operates significantly above atmospheric; oil-fill-free welded construction eliminates contamination risk in high-purity and oxygen-service applications
DMP 339 Industrial Pressure Transmitter – Compact industrial design | ATEX Ex ia | For vapour space pressure measurement on smaller vessels, drums, intermediate bulk containers (IBCs), sample cylinders, and auxiliary tanks where compact installation is required
DMP 339P Flush Pressure Transmitter with G1/4 inch port – Compact flush-mount | For vapour space measurement at compact nozzles, small-bore vent connections, and space-constrained vessel locations where condensation or fouling favours flush-diaphragm construction
Ceramic Sensor Transmitters for Corrosive Vapour Environments
Vapour spaces above corrosive liquids contain chemically aggressive atmospheres: hydrochloric acid vapour above acid storage, sulphur dioxide above spent acid tanks, acetic acid vapour above solvent recovery vessels, chlorine vapour above chlor-alkali process tanks, amine vapour above gas treating systems, and mixed corrosive condensates forming wherever vapour contacts cooler surfaces. Ceramic and PVDF wetted sensors provide the chemical resistance conventional metal diaphragm transmitters cannot sustain:
DMK 331 Industrial Pressure Transmitter – Capacitive ceramic sensor (99.9% Al2O3) | 400 mbar to 600 bar | G1/2 inch flush port for pasty/polluted media | Open port PVDF for aggressive media | ATEX Ex ia | SIL 2 | The primary ceramic transmitter for corrosive vapour space pressure monitoring; PVDF wetted port variant provides verified compatibility with HCl vapour, SO2, acetic acid, formic acid, and a wide range of organic and inorganic acid vapour environments; SIL 2 certification supports safety-critical overpressure protection on corrosive chemical storage tanks where vapour pressure exceedance could cause relief valve lifting and uncontrolled toxic or flammable release
DMK 351 Pressure Transmitter – Capacitive ceramic sensor (99.9% Al2O3) | 40 mbar to 20 bar | High overpressure capability | ATEX Ex ia (gas and dust) | For low-to-moderate-pressure corrosive vapour space monitoring where ceramic chemical resistance provides reliable long-term service above corrosive liquid storage, acid tanks, caustic vessels, and solvent recovery receivers
DMK 351 P Pressure Transmitter for the Process Industry – Capacitive ceramic sensor | 40 mbar to 20 bar | Dead-space-free hygienic connections | IS Ex ia | For vapour space measurement where corrosive condensates, sublimation deposits, or mist carryover would block conventional ports; flush-diaphragm ceramic construction prevents blockage while providing inherent resistance to chemical attack from corrosive vapour condensates
DMK 331 P Industrial Pressure Transmitter – Capacitive ceramic sensor | Flush diaphragm | ATEX Ex ia | For flush-mounted vapour space measurement on vessels processing pasty, polymerising, or heavily contaminated products where vapour-side condensation and splashing create fouling conditions requiring flush sensor construction combined with ceramic chemical resistance
XMP ci Process Pressure Transmitter with HART – Capacitive ceramic sensor (99.9% Al2O3) | 160 mbar to 20 bar | HART | Two-chamber aluminium die-cast or stainless steel field housing | Intrinsic safety (ia) and flameproof (d) options | Turn-down 1:5 | For HART-integrated corrosive vapour space monitoring with DCS asset management, predictive sensor diagnostics, and centralised instrument health monitoring across tank farms and multi-vessel process areas handling corrosive volatile chemicals
X|act ci Precision Pressure Transmitter – Capacitive ceramic sensor (99.9% Al2O3) | 160 mbar to 20 bar | HART option | Flush-mounted | ATEX Ex ia option | For precision corrosive vapour pressure measurement where ceramic sensor stability supports extended recalibration intervals across seasonal temperature cycles and multi-product storage campaigns
Pressurised Vapour Monitoring for LPG, Liquefied Gas, and High-Vapour-Pressure Products
Storage and processing of liquefied petroleum gas (LPG), propylene, butadiene, vinyl chloride monomer, ethylene oxide, anhydrous ammonia, liquefied chlorine, and other high-vapour-pressure chemicals requires transmitters engineered for sustained pressurised service where the vapour pressure itself is the critical safety parameter governing vessel integrity, relief system sizing, and product containment:
DMP 333 Industrial Pressure Transmitter for High Pressure – 100 bar to 600 bar | Piezoresistive stainless steel | ATEX Ex ia | SIL 2 | Excellent long-term stability under high dynamic pressure loads | Insensitive to pressure peaks | For vapour pressure monitoring on pressurised LPG spheres, bullet tanks, high-pressure gas storage, and liquefied gas process vessels where the vapour pressure routinely operates at elevated levels and accurate monitoring is the primary defence against overpressure; SIL 2 certification supports high-pressure trip and emergency depressurisation initiation
DMP 334 Industrial Pressure Transmitter for High Pressure – 600 bar to 2,200 bar | Thin-film sensor welded directly to pressure port | ATEX Ex ia | For ultra-high vapour pressure monitoring on supercritical fluid systems, high-pressure gas storage above the critical point, and specialist pressurised storage where vapour pressures exceed conventional ranges
DMP 334 i Precision Pressure Transmitter for High Pressure – High-pressure range | 16-bit digital signal processing | Turn-down 1:10 | Active correction of non-linearity and thermal error | For precision high-vapour-pressure measurement supporting custody transfer documentation, inventory reconciliation (mass calculation from P+T via equation of state), and product specification verification on high-value liquefied gas storage
DMP 304 Industrial Pressure Transmitter for Ultra High Pressure – Up to 6,000 bar | ATEX certified | 0.25% FSO accuracy | For ultra-high-pressure vapour monitoring on supercritical extraction systems, high-pressure research autoclaves, and specialist high-pressure chemical processing where vapour pressures exceed 600 bar
Differential Pressure for Column, Condenser, and Vapour Recovery System Monitoring
Differential pressure measurement across distillation column sections, packed beds, condenser tubes, vapour recovery units (VRUs), and vent gas treatment systems provides real-time diagnostic data for vapour-liquid equilibrium assessment, column flooding detection, condenser fouling indication, and VRU performance verification:
DPT 200 Differential Pressure Transmitter with HART – 1 mbar to 20 bar | Static pressure to 400 bar | HART | 100:1 rangeability | ATEX Ex ia / Ex d | LC display | For DP measurement across distillation column sections tracking tray-to-tray or packed-bed delta-P as the primary indicator of vapour traffic, flooding onset, and internal fouling; 100:1 rangeability covers the full operating range from startup through maximum throughput; HART connectivity enables DCS-integrated column performance trending, predictive fouling analysis, and asset health monitoring
DPT 100 Differential Pressure Transmitter – 10 mbar to 20 bar | Static pressure to 400 bar | RS485 Modbus RTU | Fast response time (10 ms) | 0.1% FSO accuracy | For fast-response vapour system diagnostics where rapid detection of condenser tube fouling, vapour recovery unit pressure excursion, vent header restriction, and column pressure fluctuation is critical; 10 ms response captures transient vapour pressure events during operational upsets
DMD 831 Differential Pressure Transmitter with Display and Contact – 1 bar to 70 bar | Dual piezoresistive stainless steel sensors | 4-digit LED display | PNP alarm contact | For condenser delta-P monitoring and vapour recovery system filter differential pressure with integrated LED display for local operator visibility and PNP alarm contact triggering maintenance notification when fouling progresses beyond the acceptable threshold
DMD 331 Differential Pressure Transmitter – 20 mbar to 16 bar | Piezoresistive stainless steel | ATEX Ex ia | 30x static overpressure | For differential pressure monitoring across vapour system components in ATEX-classified process areas including column sections, reboiler vapour circuits, and overhead condenser systems
SIL 2 and HART Transmitters for Vapour Pressure Safety and DCS Integration
Vapour pressure exceedances on storage tanks, process vessels, and pressurised systems require SIL 2 rated pressure transmitters feeding the plant SIS for high-pressure trip, emergency depressurisation, relief system activation, vapour containment valve closure, and automated emergency shutdown:
X|act i Precision Pressure Transmitter (SIL 2) – 400 mbar to 40 bar | HART | SIL 2 | Turn-down 1:10 | Flush welded diaphragm | ATEX Ex ia | Cooling element to 300 degrees C | For SIL 2 vapour pressure overpressure protection on storage tanks, process vessels, and reactor head spaces; flush welded diaphragm handles condensing vapours and mist carryover without blockage; HART supports simultaneous safety monitoring and DCS asset management; cooling element enables direct mounting on hot vessel vapour nozzles without remote seals or impulse cooling legs
XMP i Precision Pressure Transmitter with HART and SIL 2 – 400 mbar to 600 bar | HART | SIL 2 | Turn-down 1:10 | For SIL 2 integration across the full vapour pressure range from low-pressure atmospheric tank vapour spaces through pressurised LPG, ammonia, and liquefied gas storage; single product family covers the complete vapour pressure spectrum; ESD trip, emergency depressurisation initiation, and relief system monitoring with SIL 2 integrity
DMP 331i / DMP 333i Precision Pressure Transmitter – 400 mbar to 600 bar | 16-bit digital signal processing | Turn-down 1:10 | Thermal error as low as 0.02% FSO/10K | For precision vapour pressure trending where the lowest possible thermal error maintains accurate measurement during the temperature excursions that drive vapour pressure changes, supporting product quality verification, Reid vapour pressure correlation, and batch release testing
IO-Link and Digital Bus Transmitters for Tank Farm and Multi-Vessel Vapour Monitoring
Chemical tank farms, blending facilities, and multi-vessel process plants with numerous vapour space monitoring points benefit from digitalised pressure monitoring with automated device parameterisation, real-time sensor health verification, centralised alarm management, and predictive maintenance across large instrument populations:
DCT 533 P Industrial Pressure Transmitter with IO-Link – 100 mbar to 40 bar | IO-Link V1.1 | CIP/SIP cleaning up to 150 degrees C | Flush hygienic pressure port | IP 67/IP 69 | Cooling element to 300 degrees C | For IO-Link-connected vapour space monitoring across multi-tank installations where automated device parameterisation supports product changeover on multi-product tanks; sensor health diagnostics confirm measurement readiness following tank cleaning and product changeover; flush construction handles condensing vapours without blockage
DCT 553 P Industrial Pressure Transmitter with IO-Link – Capacitive ceramic sensor (99.9% Al2O3) | 40 mbar to 20 bar | IO-Link V1.1 | Dead-space-free | High overpressure capability | For IO-Link vapour space monitoring where ceramic media resistance provides compatibility with corrosive vapour atmospheres and IO-Link enables centralised device management across tank farms storing multiple corrosive volatile chemicals
DCT 531 P Industrial Pressure Transmitter with RS485 Modbus RTU – 100 mbar to 40 bar | RS485 Modbus RTU | EHEDG certified | CIP/SIP cleaning up to 150 degrees C | IP 67/IP 69 | Up to 247 devices on a single bus | For multi-tank Modbus bus architectures across large chemical tank farms where dozens of vapour space monitoring points, vent headers, and vapour collection systems require coordinated digital pressure monitoring from a centralised DCS/SCADA master with efficient wiring topology
Correlated Pressure and Temperature for True Vapour Pressure Determination
Vapour pressure is fundamentally a function of temperature. Simultaneous pressure and temperature measurement from a single process penetration enables true vapour pressure calculation (correcting measured gauge pressure for actual product temperature), Reid vapour pressure correlation, Clausius-Clapeyron trending, and thermal anomaly detection:
ATM/T.1ST Dual Output Pressure and Temperature Transmitter – Flush stainless steel diaphragm | Integrated temperature probe tip | Dual 4-20 mA outputs (pressure + temperature) | Short response time | 316L stainless steel | For simultaneous vapour space pressure and temperature measurement enabling true vapour pressure calculation from correlated P+T data; divergence between the expected vapour pressure (from the known product and measured temperature) and the actual measured pressure indicates composition change (light-end accumulation, contamination, off-specification product), dissolved gas evolution, or abnormal thermal conditions requiring investigation; reduces vessel nozzle count by combining two measurements in a single penetration
ATM/T Dual Output Pressure and Temperature Transmitter – Flush diaphragm variant with dual 4-20 mA outputs | For additional P+T measurement on condenser outlets, vapour recovery system inlets, vent header temperature/pressure correlation, and downstream vapour handling equipment
Electronic Pressure Switches for Vapour Pressure Alarm and Interlock
Automated switching outputs for vapour pressure exceedance alarm, high-vapour-pressure trip, low-pressure vacuum alarm, conservation vent performance monitoring, vapour recovery system pressure interlock, and tank overpressure protection:
DS 200 P Electronic Pressure Switch – 100 mbar to 40 bar | 1, 2, or 4 PNP contacts | 4-20 mA / 0-10 V analogue output | 4-digit LED display | IS Ex ia option | For multi-level vapour space alarm switching: independent contacts for high vapour pressure warning, high-high vapour pressure trip, low pressure alarm (vacuum protection), and vapour recovery system pressure exceedance; integrated LED display provides local vapour pressure indication for operators during tank gauging, sampling, and inspection rounds
DS 201 P Electronic Pressure Switch – 60-400 bar | Flush stainless steel diaphragm | Cooling element to 300 degrees C | 1, 2, or 4 PNP contacts + analogue output | For high-vapour-pressure alarm and trip switching on pressurised LPG, ammonia, and liquefied gas storage vessels where vapour pressure monitoring is the primary safety parameter
DS 400 P Intelligent Electronic Pressure Switch – 100 mbar to 40 bar | Hygienic stainless steel | 1 or 2 PNP contacts | 4-20 mA analogue output | 4-digit LED display | IS Ex ia | For vapour space alarm switching with clear local LED display for operator visibility during routine tank farm rounds, sampling, and manual intervention
DS 350 P Electronic Pressure Switch with IO-Link – IO-Link interface | Flush diaphragm | For digitally connected vapour pressure alarm switching on IO-Link bus architectures with centralised alarm management across multi-tank installations, automated alarm threshold adjustment during product changeover, and real-time switch health diagnostics confirming interlock readiness
Temperature Monitoring for Vapour Pressure Correlation and Thermal Management
Standalone temperature measurement for vapour space temperature, liquid surface temperature, tank shell temperature, ambient temperature, and condenser outlet temperature supporting vapour pressure correlation, thermal modelling, and environmental emissions estimation:
TTT Titan Temperature Transmitter – PT100, PT1000, NTC, PTC, or thermocouple input | Robust industrial enclosure | Stable output in demanding environments | For vapour space temperature, liquid bulk temperature, tank shell temperature profiling, ambient temperature for diurnal breathing loss estimation, and condenser performance monitoring across ATEX-classified tank farm and process areas
TTTa Titan Temperature Transmitter – Analogue – Analogue output variant | For conventional 4-20 mA integration into existing DCS systems monitoring vapour-related thermal parameters across legacy installations
Vapour Pressure Monitoring - Instrumentation Selection Guide
| Measurement Need | Recommended Product(s) | Key Feature |
|---|---|---|
| Vapour space pressure (ATEX, SIL 2) | DMP 331 | ATEX Ex ia, SIL 2, proven stability |
| Low-pressure vapour space (10 mbar) | DMP 343 | 10 mbar, excellent linearity, ATEX |
| Condensing/fouling vapour (flush) | DMP 331 P | Flush, SIL 2, Hastelloy/Tantalum, 300 degrees C |
| Precision vapour pressure (low temp coeff) | DMP 331 P i | 16-bit DSP, 1:10 turn-down |
| Pressurised vapour, no oil-fill | DMP 335 | Welded SS, spike insensitive, oxygen safe |
| Compact vessel / drum / IBC | DMP 339, DMP 339P | Compact, ATEX, flush |
| Corrosive vapour (ceramic, PVDF, SIL 2) | DMK 331 | Ceramic, PVDF, ATEX, SIL 2 |
| Corrosive + fouling vapour (ceramic flush) | DMK 331 P | Ceramic, flush, ATEX |
| Corrosive vapour, low-moderate pressure | DMK 351, DMK 351 P | Ceramic, high overpressure, flush |
| Corrosive vapour (ceramic, HART) | XMP ci, X|act ci | Ceramic, HART, ATEX |
| High vapour pressure (LPG, 100-600 bar) | DMP 333 | ATEX, SIL 2, dynamic load stable |
| Ultra-high vapour pressure (600-2,200 bar) | DMP 334, DMP 334 i | Welded thin-film, precision |
| Ultra-high pressure (to 6,000 bar) | DMP 304 | ATEX, 0.25% FSO |
| Column / condenser DP (HART, 100:1) | DPT 200 | HART, 1 mbar, 100:1 rangeability |
| Vapour system diagnostics (fast, Modbus) | DPT 100 | 10 ms, RS485, 0.1% FSO |
| Condenser / VRU filter DP (display + alarm) | DMD 831 | LED display, PNP alarm |
| DP in ATEX vapour areas | DMD 331 | ATEX Ex ia, 30x overpressure |
| SIL 2 vapour overpressure, HART, flush | X|act i | HART, SIL 2, 300 degrees C cooling |
| SIL 2 vapour SIS, HART, wide range | XMP i | HART, SIL 2, 400 mbar-600 bar |
| Precision vapour pressure trending | DMP 331i / 333i | 0.02% FSO/10K, 1:10 turn-down |
| IO-Link, flush, multi-product tanks | DCT 533 P | IO-Link, CIP/SIP 150 degrees C |
| IO-Link, ceramic, corrosive vapour | DCT 553 P | Ceramic, IO-Link, dead-space-free |
| Multi-tank Modbus bus | DCT 531 P | EHEDG, Modbus, 247 devices |
| Correlated P+T (true vapour pressure) | ATM/T.1ST, ATM/T | Dual 4-20 mA, flush |
| Multi-contact vapour alarm (ATEX) | DS 200 P | 1-4 PNP, analogue, LED, ATEX |
| High-pressure vapour alarm/trip | DS 201 P | 60-400 bar, 300 degrees C |
| Vapour alarm with display | DS 400 P | LED, PNP, Ex ia |
| IO-Link vapour alarm switching | DS 350 P | IO-Link, flush |
| Vapour / ambient / condenser temperature | TTT, TTTa | PT100/TC, robust |
| Vapour pressure PID control | PUR-94 | Dual-loop, Fuzzy Logic, Modbus |
| Simple blanketing / vent switching | PUR-99 | Two-step + PID |
| Multi-point vapour pressure documentation | CMC-N16 | 48 inputs, SCADA, Ethernet |
| Field vapour pressure verification | BAROLI 02 P, BAROLI 05 P | Portable, flush, battery |
| Tank integrity / vent leak test | DL 01 | Data logger, ATEX, USB |