IS & Ex


Safe operation of LNG tanks

September 2020 IS & Ex

The rapidly increasing supply and demand for LNG is driving a new and dynamic business worldwide. The number of small to medium scale terminals is increasing, while at the same time, tank sizes are increasing in new-design centralised terminals. These developments bring complex challenges to the safe and efficient managing of LNG inventory in tanks, terminals or other storage facilities.

The storage of LNG at cryogenic temperatures presents unique challenges that must be appropriately handled to ensure safe and efficient operation. A typical LNG tank requires a wide range of instruments to measure liquid level, density, liquid and vapour pressure and temperature, skin temperature and more.

Additionally, stratification occurs when the product in the tanks forms layers with different densities temperatures. For safe operation, users need to ensure that two layers of different densities are not rapidly mixing and releasing large amounts of gas, known as rollover.


Endress+Hauser’s innovative instrumentation and advanced inventory management solutions for LNG storage tanks ensure safe operation of plant and high levels of inventory transparency. These solutions offer a wide set of functionality and benefits, including:

• High precision servo tank gauging with the intelligent Proservo NMS8x for constant primary level measurement, or in redundant operation, to accurately and reliably monitor level. It performs density profiling as required.

• Separate servo or radar gauges for high level alarms ensure 24/7 plant safety.

• The safe operation of LNG tanks to ensure that different densities and temperatures do not create layers that could result in rollover effects: LTD (level temperature density) gauges monitor density changes in different LNG layers, creating a density and temperature profile of the tank.

• Highly accurate pressure transmitters provide alerts for any significant pressure changes in the LNG tanks and boil off gas management.

• Redundant inventory management system to ensure 24/7 plant availability.

• Stratification and rollover prediction software – not only important for knowing what is happening in the tank, but also helps you determine the next process actions.

• Skin temperature for cooldown and leak detection and temperature monitoring software.

The rollover prediction software within Tankvision allows users to visualise the evolution of temperature, density and layer thickness of the stratified layers within a tank. The software predicts rollover and enables upfront countermeasures. The change in boil-off rate and vapour pressure can also be visualised with time.

LNG tank management system

The Tankvision LMS inventory management system features reliable LNG real-time management. It is a truly open and redundant system and allows tank redundant data, a multi-user system with remote access capability. It can be used as a client/server or standalone package and provides the following features: inventory calculation, gauge operation, LTD detail monitoring, alarm generation, real-time trending, profile viewers, stratification analysis, skin temperature distribution graphics and schedule commands.

Rollover prediction software

The rollover prediction algorithms are based upon a lumped parameter model using energy and material balance equations. It allows the user to visualise the evolution of temperature, density and layer thickness of the stratified layers within a tank from an initial condition for temperature, layer depth and composition. The change in boil-off rate and vapour pressure can also be visualised with time. The model can be run for any profile available in the history by using the manual profile selection or automatic selection. The model can incorporate various tank operations such as tank filling (top or bottom), tank emptying (top or bottom) and external recirculation.

Cool down and leak detection software

The cool down and leak detection sensors, located around the base sides and roof of the LNG tank, are used to detect any abnormalities in the shell insulation that may result in a leak of product. The software provides the following functionalities:

• View menu – skin temperatures.

• Temperature maps.

• Shell layer drop down selection.

• Historical skin temperatures.

• Thresholds/trends/alarms.


Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Tube connector for Ex areas
May 2020, Parker Hannifin - Sales Company South Africa , IS & Ex
Parker Hannifin has extended its Phastite permanent instrumentation connection range, which is now available in a number of corrosion-resistant alloys (CRAs), including Alloy 825, 625 and Super Duplex, ...

Read more...
Safe and efficient water and wastewater treatment
October 2020, Endress+Hauser South Africa , System Integration & Control Systems Design
Depending on the application and the industry, water needs to have different properties to ensure the quality of finished products and the overall safety of production.

Read more...
Safety controllers with diagnostics
October 2020, Turck Banner , IS & Ex
The combination of an intuitive user interface and diagnostics makes it easy to design and troubleshoot complex safety systems in just a few clicks.

Read more...
Endress+Hauser strengthens presence in the Middle East
October 2020, Endress+Hauser South Africa , News
Endress+Hauser is strengthening the Group’s presence on the Arabian Peninsula with the establishment of Endress+Hauser Middle East.

Read more...
Real-time location system
September 2020, Extech Safety Systems , IS & Ex
With worker safety becoming an ever-increasing focus for many businesses operating within process industries, iTAG X30 delivers a solution that allows high levels of location accuracy across their entire site.

Read more...
Sensor technology now in use in explosion-protected areas
September 2020, Pepperl+Fuchs , IS & Ex
Increased customer demand for hazardous areas requirements that can be met using sensor technology require sensors to be fitted in potentially hazardous locations, posing ever greater challenges.

Read more...
New iTEMP transmitter with Bluetooth
September 2020, Endress+Hauser South Africa , Temperature Measurement
Endress+Hauser’s new iTEMP TMT142B temperature transmitters deliver highly accurate and reliable measurements, wireless communication via Bluetooth and user-friendly operation packaged in a robust single-chamber field housing.

Read more...
PyroStorm protection for control equipment
September 2020, Alien Systems & Technologies , IS & Ex
If you work at a large industrial plant or mine, you may have noticed those hydraulic lubricating oil packs, or perhaps the diesel generator sets, oil store rooms, pump rooms or flammable liquids stores, ...

Read more...
Endress+Hauser strengthens the protection of intellectual property
August 2020, Endress+Hauser South Africa , News
For 20 years now, a separate department at Endress+Hauser has been dealing exclusively with the protection of intellectual property. In 1999, the company merged and realigned all activities in this field. ...

Read more...
PyroStorm provides cost-effective fire protection for control equipment
August 2020 , IS & Ex
If you work at a large industrial plant or mine, you may have noticed those hydraulic lubricating oil packs, or perhaps the diesel generator sets, oil store rooms, pump rooms or flammable liquids stores, ...

Read more...