High Temperature Sight Glass Type 323 for bolting onto DIN and ANSI flanges

Short description - High Temperature Sight Glass for bolting onto flanges

The ACI Tank sight glass Type 323 is a modification of our Type 321, suited for an extended range of applications, specifically at increased temperatures. It is used as a viewport or illumination window for the interior of enclosed pressure vessels like tanks, silos or boilers.

The PTFE enclosed resilient gasket technology used in our sight glass Type 321 is not suitable for use above 200°C. To alleviate this, we use high quality graphite composite gaskets as replacement. With this modification, the sight glass Type 323 can be used up to the maximum service temperature of 280°C with borosilicate glass according to DIN 7080, which can be increased to 300°C by installing a protective mica sheet.

Type 323 can be used for operating temperatures up to 400°C when high performance materials like quartz or sapphire glass are used, and even up to 1000°C as a special construction on request.

Because Type 323 uses the same off load sealing technique as our proven sight glass Type 321, it offers the same advantages. The glass disc is completely surrounded and protected by the fitting, and can be replaced on location as one single part. The fitting is delivered preassembled and optionally tested for pressure resistance and leakage, allowing you to completely rely on our quality products!

Like Type 321, Type 323 is available with light fixtures using halogen or LED light sources

Read on for more technical information and our product video!

Technical Details


Base flange:
1.4724 / 1.4762 / 1.4828 / 1.4841 / 1.4845 / 1.4571 / 2.4605

Cover flange:
1.4724 / 1.4762 / 1.4828 / 1.4841 / 1.4845 / 1.4571 / 2.4605

Quarzglas, Saphirglas

Graphit, novamica, thermex


assembly for bolting straight onto DIN EN 1092 or ASME flanges

Nominal size

DN40 up to DN200


PN10 or on request


400°C / Special versions up to 1000 ° C are possible on request

Optional versions are possible.

Take a look at the animation video, here you can see the structure of our high temperature tank sight glass type 323 perfectly.

DN Di H (PN10) H (PN25) Da L K
40 48 36 38 according to DIN EN 1092-1
50 65 38 41
80 36 46 50
100 100 46 59
125 125 54 66
150 125 54 37,2
200 150 54 37,2
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