Container sight glass
A container sight glass is a type of sight glass , usually consisting of a pane of borosilicate glass , which is framed in steel flanges together with flat seals.
Common designs of container sight glasses are based on the standards DIN 28120 for welded sight glasses and DIN 28121 for screwed sockets.
Based on the specifications of these standards, further designs for different areas of application are also established on the market.
Sight glass fittings according to DIN 28120
In the case of sight glass fittings according to DIN 28120, the glass plate used is placed together with the media-side seal in a recess in the already welded-in base flange and fixed from the outside by a counter flange provided with a protective pad. With this design, the glass plate can be exchanged with relatively little effort.
Such fittings are usually approved up to an operating temperature of 280 ° C, but this permissible temperature can be increased to 300 ° C by using a protective layer made of mica . This protective layer also increases the service life of the glass in aggressive media.
Sight glass fittings according to DIN 28121
In the case of a fitting according to DIN 28121, the seal is different from DIN 28120 by means of a force shunt. The steel flanges of the valve are pulled together by pre-tensioning screws until they make contact, which means that a mostly PTFE- encased soft material seal is deformed in a defined manner. This results in a reliable sealing of the valve. In the event of damage, the entire valve is usually replaced here. If components such as seals or glass are to be changed, this is done by the manufacturer
Individual evidence
- ↑ P. Götz: Container sight glass type 320. ACI Industriearmaturen, January 31, 2020, accessed on January 31, 2020 .
- ↑ Round container sight glasses according to DIN 28120. Accessed on January 18, 2018 .
- ↑ Round container sight glasses according to DIN 28121. Accessed on July 14, 2017 .
- ↑ P. Götz: Container sight glass type 321. ACI Industriearmaturen, February 3, 2020, accessed on February 3, 2020 .