LNG Terminal Monitoring

A leak of a pipe or tank leads to very low temperatures that are detected and precisely located within a few meters with the fiber optic sensor cable that is installed along the pipe, in the tank annulus or around impoundment basins. Various alarm thresholds can be individually set in different alarm zones offering pre- and main alarms. AP Sensing’s smart alarm features cover maximum, minimum and gradient alarms to ensure best performance. Our DTS solution offers the lowest false alarm rate in the industry; alarms are transmitted to the SCADA/DCS system through standard protocols like Modbus TCP and/or hard-wired relay contacts. 

The sensor fiber is deployed in the annulus between the two tank walls during tank construction. If a leak occurs, cold or cryogenic fluids will cause a drop in temperature of the annulus space.  Due to the low temperature of the fluid, the DTS system rapidly identifies even very small leaks with very low levels of false alarms.

Liquefied gas is also quickly detected by routing DTS sensor cable around the perimeter of the spill containment areas. When leaking material reaches the containment areas, the temperature decreases, triggering an alarm. 

The DTS monitors the entire pad area and heating system in real time, down to one-half meter spatial resolution. The sensor cable is deployed in the heating element conduit within the pad and provides temperature data every half meter along its path. In addition to monitoring functionality, the temperature data also minimizes power consumption. By identifying hot and cold spots, heating efficiency is improved. From the jetty to the process areas and on to the tanks: The AP Sensing DTS solution provides thermal gradient information during cool-down—ensuring that pipe stress is kept within specified limits. It also identifies pipe leak points and possible insulation problems that cannot be seen by a visual examination. Pipelines that transport liquefied gas, such as LPG, ammonium and hydrogen also benefit from the unique ability to quickly detect leaks and pinpoint them precisely. Thus, serious consequential damage can be reliably prevented.

AP Sensing’s DTS solutions are compliant with various regulations around the world. The operator receives all critical information, such as temperature, even for inaccessible locations inside the tank. Our system is certified for highly explosive atmospheres (ATEX/IECEx), and according to IEC 61508 SIL2. It is virtually maintenance-free and suitable for remote areas which are difficult to access. This ease-of-use comes with highly reliable performance, a low-power laser for safe use and a long product life  . Part of our offer includes sensor cables that fit the needs of the application: robustness and a wide temperature measurement range.