Naxys - Local Leak Detection (LLD)
The Naxys Local Leak Detector (LLD) is an ultrasensitive instrument within the category DNVGL* is referring to as “point sensing sensors”. The LLD provide real time leak rate and will detect even single gas bubbles passing the sensor head. In line with DNVGL recommended practice the LLD is designed to be installed over critical points considered to have the highest leak probability and with a potentially higher leak rate – this will typically be subsea components with high pressure flow and more complex geometry like valves, flanges, joints etc.
Please note that a limitation to “point sensing sensors” is that direct contact with the leaking medium is required. Seawater currents or buoyancy effects may lead the leaking medium away from the sensor. We solved this by installing a collector for hydrocarbons above the area considered critical and the LLD is installed at the top of the collector, see illustration below. To be in line with the recommended practice by DNVGL, we recommend that a point sensing sensor is combined with a sensor able to perform detection over an area (not limited to point sensing), e.g. the Naxys ALD sensor.