The systems of separation of the light liquids (for example gas, oil and derivatives), commonly called “oil separators”, are currently regulated by regulation UNI EN 858 parts 1 and 2. It recommends the employment of the oil separators for the treatment of drainage waters in all the activities that produce oily waste waters, or dispose of oily residues from large polluted lots for which arises the need for meteoric storm water treatment. Entered into this category are mechanical workshops, fuel distributors, car washes, warehouses, parking lots, roads, etc. All the oil separators of the series are certified based on the outcomes of the tests prescribed by the cited regulations. In particular:

• the concrete and the iron casings of the reservoirs have been subjected to the tests specified by point 8.1 of UNI EN 858-1 with consistent results to requirement demands of point 6.2 of the same regulation;
   

• all the typology of the employed reservoirs have been subjected with positive outcome to the water sealant tests specified by point 8.2 of UNI EN 858-1;
   

• the automatic closing devices have been subjected to the tests specified by point 8.3.2 of UNI EN 852-1 with results consistent to requirement demands by point 6.5.3 of the same regulation;
   

• the nominal diameters of the piping and the volumes are conformed to the limits prescribed respectively from prospectus 2 of UNI EN 858-1 and from prospectus 5 of UNI EN 858-2;
   

• the basic sizes of the oil separators have been determined on the basis of tests carried out using the equipment specified by point 8.3.3.1 of UNI EN 858-1 following the test methodology prescribed from the same norm.

The choice of the basic sizes of the oil separators for the specific applications must be carried out following the calculation methodology described by point 4.3 of UNI EN 858-2.

The oil separator provides for the removal of the muddy and oily substances from waters by means of the employment of one single reservoir. So equipped, the reservoir operates two processes: “sedimentation” and “separation”. The first one is in charge of the separation and accumulation of the solid sediments (sludge, lime, sand, etc), while the second provides for the separation and accumulation of the oily suspensions (oils, hydrocarbons, etc). Inside the oil separator there is one floater valve for automatic closing in case of excess oil from the separator. The oil separator is of class 1 (coalescent separator according to the definition of table 1 of UNI EN 858-1) and has a coalescence filter grafted to the escape duct of the separator. Thus conformed, the oil separator works as follows:

• The waters to be treated enter into the oil separator where the solid sediments are deposited on the bottom, while the extolled/decanted water and the lighter substances rise back to the surface. The clarified water below crosses the coalescence filter and enters into the drainage conduct.
   

• During the filtering process the oily microparticles that escape floatation and are dragged by the water, coalesce, forming more consistent suspensions that separate rising back to the surface.
   

• If the thickness of the floating oil layer exceeds the limit prescribed by the norm (point 6.5.2 of UNI EN the 858-1) the floater valve is closed.
   

• When the reservoir is full it is necessary to provide for the extraction and the removal of the oil contained through auto discharge.
   

• Periodically it is necessary to wash out the filter with running water.
   

• When the cargo conditions are compatible with its basic size, the oil separator is capable of removing the oily substances present in the water until a content of residual oil is not more than 5 mg/l.

The separation system of oils and hydrocarbons, of the MUSILLI NS W200 series, is manufactured with monolithic reservoirs prefabricated in reinforced vibrated concrete to high resistance, verified for street cargos of antiseismic category 1, and complete with cover slab prefabricated in carriageable reinforced vibrated concrete verified for cargos of antiseismic category 1, with bumper to bumper inspections and D400 class valves.

The reservoirs are equipped with a coalescence filter fortified with a floater stopper for security and eventual alarm option.

The system is dimensioned and constructed as indicated in the Lgs. D. no.152 dated 4/3/2006 art. 113 part III, produced, controlled, and certified to regulation UNI EN 858.

The system is recommended for the treatment of meteoric waters that contain hydrocarbons, and drainage waters derived from the industrial activities and not those that produce oily sewage.

The system is constructed by a company in possession of Business Quality System certification of UNI EN ISO 9001:2008 certified ICMQ. .