Vacuum sight glass with welding ends | ACI Industriearmaturen GmbH

Vacuum sight glass type 390V - with welding ends

Brief description: Vacuum sightglass fitting with welding ends according to DIN EN 1092

The ACI tank sight glass type 390V is a round tank sight glass for welding to open pipe sockets and tank walls.

Also here, the highly resistant Maxos® safety sight glass according to DIN 7080 for temperatures up to 280°C, which has proven itself in industry, serves as a sight glass. On the connection side of the glass holder there is a welding end with dimensions corresponding to the connection diameters and wall thicknesses specified in the DIN EN 1092-1 standard. This allows the sight glass type 390V to be welded onto most open pipe ends without additional preparation.

The base and top flanges are available in standard steel and stainless steel grades with pressure vessel approval, for example P265GH, 1.4571 or 1.4404. High performance alloys such as Hastelloy or duplex steel are also available on request.

The borosilicate glass pane is sealed with high-quality seals. For most applications we recommend the proven O-rings according to DIN 11851 made of NBR, EPDM, SILIKON or VITON. For chemically demanding applications we use pure or modified PTFE and other special materials.

Our tank sight glass type 390V can also be equipped with cleaning devices such as wipers SWI if required. On request, we can equip the cover flange of Type 390V with mounting holes for lighting at the factory, and can supply you with suitable luminaires with LED lights directly with your order.

Technical data


1.0460 / 1.4301 / 1.4306 (F304L) / 1.4404 (F316L) / 1.4410 (Super Duplex) / 1.4435 (F316L) / 1.4462 (F 51) / 1.4529 (Alloy 926) / 1.4539 (Alloy 904L) / 1.4541 (F321) / 1.4547 (F44) / 1.4550 (F347) / 1.4571 (316Ti) / 1.4828 / 1.4841 / 1.4876 ( Alloy 800H) / 1.4878 / 1.7335 / 2.4068 (Alloy 201) / 2.4360 (Alloy 400) / 2.4375 (Alloy K500) / 2.4602 (Alloy C-22) / 2.4605 (Alloy 59) / 2.4610 (Alloy C-4) / 2.4816 (Alloy 600) / 2.4819 (Alloy C-276) / 2.4856 (Alloy 625) / 2.4858 (Alloy 825) / 3.7035 (Titan)


Sight glass with welding end according to DIN EN 1092

Nominal size:


Nominal pressure:

PN16, PN25, PN40, PN63 / PN100 / PN160


PTFE / FKM / NBR / C4400 / Silicone /



With soda-lime glass up to max. 150°C

With borosilicate glass up to max. 280°C

With borosilicate glass & mica screen up to max. 320°C

With quartz glass for temperatures up to 1000°C (depending on the material combination)


Optional versions are possible.

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Vacuum sight glass with welding ends