Continental Trade Sp. z o. o.


Type 330 - PN16-35



The ACI level indicator Type 330 is an easy to mount fitting for the industrially proven borosilicate sight glass plates according to DIN 7081. The base flange of Type 330 is set into the wall of a container or pipe and is fixed all-round with a welding seam. The base flange has an indentation for glass and seals, which are held by a cover flange. Type 330 only needs a very low torque for the fixing screws, whilst still achieving very reliable sealing.

Type 330, like most of our fittings, is available in a range of materials, including standard types of container steel such as S235, or standard stainless-steel alloys such as 1.4571 or 1.4404, but high-performance materials such as Hastelloy or duplex alloys are available on request.

For the sealing, we use tried and tested high-quality flat seals from well-known manufacturers such as KlingerSIL C4400 or novaphit MST. It is also possible to supply pure PTFE seal plates and soft seals such as NBR or EPDM directly.

The industry norm DIN 7081 includes the use of sight glasses of different lengths in the Transparent” and “Reflex” versions. Transparent glass means simple, smooth glass plates. This type can, should the operating conditions require it, be fitted with protective layers made of mica or other materials such as KEL-F. We recommend the reflex type, if operating conditions allow it, for use with clear, colourless liquids. Due to the grooves contained in this type, the meniscus in the liquid phase can be seen clearer than with the transparent variety.

Read on for technical data and detailed views.



Base and top frame: 
1.4571; 1.4404, 1.4462, RSt 37-2 / H II / Other materials on request


depending on the application

Reflections -or- Transparent glass according to DIN 7081 or DIN 8903

Rectangular Sight Glass as level indicator for visual inspection of tanks, boilers and silos

Nominal size:
size from 140 mm up to 1000 mm 
Other sizes on request

Nominal pressure:
PN 16 or PN 40
For operating pressures up to max. 35 bar depending on the model

tmperature: 100 ° C or 243 ° C
depending on the glass and seal selection.

Special Feature:
Lloyd’s Register Design Approval available

Optional versions are possible.

Gasket selection:

PTFE (200°C)
FKM (200°C)
NBR (100°C)
C4400 (150°C)
Silicone (200°C)
EPDM (140°C)
Graphite (320°C)

Installation instructions:

After welding in the base flange, check whether the sealing surfaces have warped! If necessary, rework must be carried out. The operating pressure does not apply to the base frame, which must be checked together with the pressure device according to AD data sheet B9!

BL = overall length / SL = visible length

BL SL Concealed view Kg(16 bar) Kg(35 bar)
140 79 0 2,8 3,4
170 124 0 3,2 4,0
220 174 0 4,0 5,0
250 204 0 4,6 5,7
300 264 0 5,3 6,7
310 264 0 5,6 7,0
350 304 0 6,3 7,8
370 324 0 6,6 8,2
400 354 0 7, 8,9
500 454 1x46 9,1 11,4
600 574 1x46 10,7 13,4
620 574 1x46 11,1 13,9
700 654 1x46 12,5 15,7
740 694 1x46 13,2 16,5
800 74 1x46 14,2 17,8
930 884 2x46 16,7 20,9
1000 954 3x46 18,2 22,8

Take advantage of our 360 degree 3D view for a perfect all-round view of our product.

Take a look at the animation video, here you can see the structure of our rectangular tank sight glass type 330 perfectly.

Download data sheet:

While every attempt has been made to verify the source of the information, no responsibility is accepted for accuracy of data.

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