Type 391 circular sight glasses are manufactured from high-quality 1.4571 (316Ti) stainless steel, a material trusted by our customers. The glass used is industry-standard borosilicate glass, in accordance with DIN 7080 (or to customer specifications).
Sealing is achieved using flat gaskets selected to suit the specific process requirements, available in a wide range of materials. In addition to fibre gaskets, high-performance materials are available, such as PTFE (Teflon®), NBR, novaphit® MST-XP, KlingerSil® C4400 and many other gaskets from recognised brands.
Where the maximum operating temperature of DIN 7080 borosilicate glass is insufficient, or where process conditions present additional risks, a specially adapted mica protective disc can be fitted to the sight glass to provide extra protection against heat and steam. For further protection against aggressive chemicals or caustic solutions, the glass can be coated with FEP or Halar®.
Like other circular sighting products, the 391 sight can be fitted, on request, with an SGW-type sight wiper and LED lighting.
TECHNICAL SPECIFICATIONS – Circular sight glass type 391
| Flange Material: | Base Flange: 1.4571 (standard) Cover Flange: 1.4571 (standard) Other materials on request |
| Seals: | PTFE, NBR, silicone, EPDM, FKM |
| Nominal size: | DN100 to DN350 |
| Temperature / Glass: | Up to 280 °C with DIN 7080 borosilicate glass |
| Optionals: | Escova de limpeza SGW em PTFE ou silicone Iluminação LED para zonas EX e Não-EX Proteção visor FEP (para valores de pH elevados) Mica de proteção Designs especiais sob consulta |
