WEKA provides a new solution for corrosion protection of Visual Level Indicators (VLI) in explosion hazardous areasWEKA VLI is a reliable option for visualising the current fill level inside tanks. For some applications, the liquid to be measured can be very aggressive. A multinational Swedish company was searching solutions for a specific application in cleaning of drilling sludge on their FPSO (Floating Production Storage and Offloading Units). The already existing design using materials in 316/316L needed to undergo a retrofit as they were corroding to fast. WEKA was chosen as the specialist to provide the adequate solution. To insure flawless magnetic transmission, the float chamber is always made out of a non-magnetic material which in most cases is standard stainless steel alloy. These materials are generally sufficient for most applications in regards to corrosion resistance. For this special application however other materials needed to be used. Plastic level gauges were out of question due to the requirement for ATEX and higher graded nickel alloys were too high in material costs. WEKA could provide an excellent solution with Halar coating (ECTFE) as a compromise with excellent corrosion resistance values, explosion protection compatibility and price. Halar is resistant to organic solvents, caustic soda, hydrochloric acids, chlorine gas and others. It offers much better protection than for example Teflon (PTFE). The coating thickness is around 0.2mm only and therefore perfect to be used with standard WEKA level gauges. Most important is however that WEKA was able to find a supplier for Halar coatings and still fulfil the requirements in accordance with 2014/34/EU (ATEX) or comparable regulations (e.g. IECEx). This makes Halar coating a very cost-effective alternative product for highly corrosive liquids in the low pressure area including explosion protection.
For over 50 years WEKA AG has been building and selling visual magnetic level indicators. Although or even due to our long-lasting experience and specific knowhow, we never get tired to further optimise our instruments and adapt them to requests from the market and our customers. WEKA AG usually recommends fixation brackets for level gauges with a connection length of more than 2 meters. The main reason is to further stabilise long instruments mounted on a tank. The bracket is usually welded on at a predetermined position from customer. Especially outside the stabilising effect is quite significant where there could be unfavourable environmental or weather conditions. Sometimes welded on fixation brackets may prove to be problematic for example when an existing tank may not have any counter brackets mounted. Also when a new tank is still in planning, the end-user may not yet know exactly where the positioning of brackets may be. In these cases a fixed location of our brackets may be cumbersome. Several times our customers suggested finding a solution for flexible fixation brackets. Instead of welding brackets on to the indicator chamber, they could be mounted by using hose clamps as a gripping method. This would allow a moving of the device up and down the float chamber at any time. WEKA product management and design department took up this good idea and developed a new flexible fixation bracket. The task was that the same bracket can be used for all level indicator models alike. After extensive test we are happy to implement this development in to our standard range of goods.
For many years now WEKA has been a strong partner in the ship building business. Countless ships are roaming the seas and many of them do have WEKA level gauges mounted on to their tanks insuring easy readability and reliable function. Depending on the purpose of the vessel there can be as many as 50 level indicators on board. Before launching, ships must undergo a complicated process of certification and many notified bodies are making sure that the vessel is according to specifications and standards so security can be insured. As part of our excellence, WEKA has many permanent approvals with most important notified bodies for the distribution of our products in to the ship building industry. RINA SERVICES S.p.A., placed in Genoa-Italy is one of these entities delivering services of classification, certification, testing and inspection to guarantee excellence to organisations in the marine, environment and energy, infrastructures, transport and logistics, quality and safety sectors. We are happy to announce that our type approval certificate from RINA has recently been updated. It is valid until 14th January 2021. SmartLine, all StandardLines and Top of Tank units are covered in this approval as well as magnetic switches 31130 (SPST) and 31160 (SPDT).
Each type of industry has its particular features. Whether in petro chemicals, general mechanical engineering or ship building – the specifications vary in physical properties, preferred materials all the way to cable standards. Also in liquid level measurement and in our case the magnetic level indication (Visual Level Indicator – VLI), the demands have to be met. By adding electrical accessories such as magnetic switches or/and level transmitters a VLI can be upgraded to become a reliable system. These can be used as actuator for pump and valve actions as well as analysing points within an SPS or computer system. Apart from the choice of materials and adherence to standards, the electrical connection is furthermore an important factor. Integrated cables of 3m, 5m, 10m and 20m length are usually long enough to connect easily to a junction box or a circuit branch. However it is difficult to find a cable suitable for all requested requirements. Halogen free or chemical resistance are just a few of the demands. Furthermore important are the temperature range and type of shielding. In order to create a universal interface allowing the customer to use his own cables, WEKA has launched a new magnetic switch series using M12 plug-connectors. The M12 thread is according to IEC 61076-2-101 standard and is readily available worldwide. The main advantages are: A mating plug either straight or angled can be purchased as well and be mounted on to the customer’s cable. Or else a cable with already injectionmoulded mating plugs can be used. The magnetic switch with M12 plug-connectors is moreover lower in price than their cable-using counterparts. They are easy to install and to be swapped in case of replacement. Finally they offer all the well known advantages such as change-over technology, high loading capacity and an extremely robust stainless steel casing. Each VLI can be upgraded with any kind of magnetic switch even if the level indicator has been in use for decades.