A sight-glass-fitting can be used to observe and check tanks like silos, storage tanks or pressure vessels. The exceptionally pressure and temperature resistant glasses allow you to see the inside of the tank for visual inspection. The container sight glasses from NieRuf come in two models: as rectangular or circular sight glasses. The rectangular sight-glass has one long side and two shorter ones. Thus it is often welded onto the tank in a vertical way, which allows you to keep an eye on the filling level. The circular sight-glass is used in silos or boilers. The round glass allows for a larger field of view. After welding the mounting flange, you should check whether the sealing area has moved. In this case, reworking might be required. The operating pressure is valid not only for the base frame and needs to be checked with the pressure device according to technical bulletin AD B9. Please contact us if you need further information.