Home About us Press FAQs Contact Us Testimonials
Quality Brands                  Quality Products                  Quality Service
Industrial Trading Solutions Limited
6 Station Road
B46 1HT

Tel: 01675 465191
Fax: 01675 464429
email: click here

Alfa Laval Sight Glasses.

Print   Print this page      Email   Email to a friend

The bolted sight glass is used for visual control of processes
inside vessels which typically are under high pressure and have
temperatures. The sight glass is used in chemical, pharmaceutical
and cosmetical industries as well as in dairies, breweries and
other food industries.
Standard Design
The sight glass consists of a base flange, a cover flange, gaskets,
a glass disc, nuts and studs. The sight glass is to be welded into
or onto vessel walls and it corresponds in its construction and
assembly to the dimensions and constructional guidelines of the
DIN specification 28120. The respect of the DIN prescriptions for
the flange thicknesses guarantees a distortion free location of the
sight glass disc in case of correct welding. The pressure resistance
of the glass disc is, of course, dependent on the care with
which the bolts and nuts are tightened (always working on
diametrically opposed pairs). For lubricated bolts, Ra = 0.1mm,
the recommended tightening torque values (in Nm) are indicated
in the table on page 2. The glass discs are made of borosilicateglass
to DIN 7080 which means that the maximum operating
temperature is 280C. All steel parts available with material
certificate EN10204.
Technical Data
Max. product pressure: Max. 1000 kPa (10 bar)
Min. product pressure: Full vacuum.
Temperature range: -10C to +140C
(EPDM), (higher temperatures up
to 280C with gaskets of Klingersil).
Fig. 1. Sight Glass DIN 28120.
Base flange: AISI 316L, material certificate 3.1B/AD-W2.
Cover flange: AISI 321, material certificate 3.1B/AD-W2.
Gaskets: Klingersil C4400 (cover side)/EPDM
(product side).
Glass disc: Borosilicate to DIN 7080, material certificate
2.2 (max. 280C).
Bolts or studs: To DIN 938/934 in A2-70.

The numbers in the following installation instructions refer to the
drawing above.
After having correctly welded the base flange (1) onto or into the
vessel wall, the gasket (2), the sight glass disc (3), the gasket (4)
and the cover flange (5) are mounted one after the other and then
the nuts (6) are tightened, always working on diametrically
opposite pairs. The above indicated tightening torque values
have to be strictly respected. Additional information may be
taken from the DIN specification 28120.
- Product wetted side of gasket in Klingersil C4400.
- miniVISION light fitting.
When ordering, please state the following:
- DN size.
- Material type of product wetted gasket side.
- miniVISION light fitting, if needed.
Some of our Suppliers
Web Design Birmingham and Search Engine Optimisation (SEO) developed by EvolveNet