FSO-EXT (UREA) Extended Diaphragm Lens Type

The FSO-EXT is typically used in combination with (differential) pressure transmitters for level, flow and pressure measurement, in those applications where the diaphragm need to be flush with the vessel wall or where insulation layers need to be passed. 

The FSO-EXT is recommended when extended seals are required fully in exotic materials and/or when special grade cover flanges are required for pressure temperature rating. 

The FSO-EXT lens type seal has a screwed connection into the flange. The seal body is made of bar stock or forged material. Its pressure rating is defined by the back-up flange and as such it can be used for pressure ratings in RF or type B1 facings. This design is often used in UREA and fertilizer industry, as it is a typically design of the main contractors.