NORIS specializes in sight glasses and visual inspection for industrial applications where process monitoring and hygiene are crucial. As a fittings factory, we combine the quality of NORIS with our engineering expertise: we not only supply standard products, but also configure complete systems – including modification, automation and documentation.
For visual inspection of liquids and gases.
For inspection and process monitoring in tanks and reactors.
For CIP/SIP processes, aggressive media and ATEX areas.
Adaptation to existing systems – including special connections and gaskets.
Hygienic sight glasses for sterile processes.
Visual inspection for aggressive media and hazardous zones.
Sight glasses for hot water and steam systems.
Inspection solutions for circulation systems and treatment.
Flow sight glasses in DN 15 to DN 250, PN 16 to PN 40.
Manufactured above DN 100 and in PN 40 based on DIN 3237.
Two size ranges: DN 15 to 50 and DN 65 to 250.
Operating pressure 16, 25 or 40 bar with a flange connection to DIN.
Operating temperature 150 °C or 280 °C depending on version.
Rotor for permanent visual inspection, flap as a robust flow indicator.
No electronics, no calibration – the visual inspection works purely mechanically.
We trade in NORIS sight glasses and supply from the manufacturer range. The series described below is the one we supply most often – we can source the complete NORIS range, including series not listed here.
A flow sight glass shows the flow, colour and condition of the medium directly in the pipeline – without auxiliary power, without electronics, without calibration. For visual monitoring in process lines this is often the simplest and most durable solution.
| Feature | Value |
| Standard | DIN 3237; above DN 100 and in PN 40 based on DIN 3237 |
| Nominal sizes | DN 15 to DN 50 and DN 65 to DN 250 |
| Pressure ratings | PN 16, PN 25 and PN 40 with a flanged connection to DIN |
| Operating pressure | 16, 25 or 40 bar |
| Operating temperature | 150 °C or 280 °C depending on version |
| Materials | grey cast iron EN-GJL-250 up to a maximum of 16 bar, or stainless steel 1.4408 |
| Internals | with rotor or with flapper – both make even low flow visible |
| Alternative connections | female thread G to BSP or NPT |
Note on sizing: the 16 bar version is available only with borosilicate glass. Anyone needing higher pressure ratings chooses PN 25 or PN 40 and therefore the stainless steel version.
Both internals serve the same purpose – making the flow visible even when the medium is clear. The rotor turns in proportion to the flow velocity and is suited to permanent visual monitoring. The flapper deflects and mainly shows whether there is any flow at all – more robust when the medium is contaminated.
Our standard is the unchanged series version from the NORIS range. In addition we can offer for NORIS products:
Yes, we offer modifications such as special materials, special connections and ATEX-compliant designs.
For food, pharmaceutical, chemical, energy and industrial plants.
Yes, we supply ready-to-install units including sight glasses, accessories and documentation.
The starting point is your enquiry with medium, pressure and temperature. From this we size the appropriate NORIS version and agree the accessories and test scope with you.
Because of the high reliability, quality and specialization in hygienic and ATEX-compliant visual inspection – and our experience as a partner.
