Technical Info Glass Industrial Apparatus

1. Basic features of SIMAX glass
All glass parts are made of borosilicate glass 3.3 SIMAX.
This type of borosilicate glass is characterized by high chemical resistance, low coefficient of lin-
ear thermal expansivity and thus high resistance against temperature changes. Properties of the
SIMAX glass are under a permanent supervision and are certified in accordance with ISO 3585.
Chemical composition
O + K
O Al
80.6 13 4 2.4
1.1. Chemical resistance
Products from SIMAX glass feature high resistance against the effects of water, steam, acids, salt
solutions, and relatively good resistance against alkalis. For these reasons, SIMAX glass is used
in cases where high chemical resistance and neutrality against stored or working substances are
required for the products, i.e. in chemistry, laboratories, health care, pharmaceutics, food industry,
etc. Chemical resistance is assessed by standard international methods defined by ISO standards.
Acceptable value Max. value attained
Method according to standard ISO for SIMAX glass
Class Value Class Value
Resistance against water at 98 °C according to ISO 719, loss of alkalis
+g/g HGB1 31 HGB1 25
Resistance against water at 121 °C according to ISO 720, loss of alkalis +g/g HGA1 62 HGA1 28
Resistance against acids according to ISO 1776, loss of weight +g/dm
1 100 1 11
Resistance against alkalis according to ISO 695, loss of weight mg/dm
A2 175 A2 120
1.1.1. Resistance against water at 98°C
The test is carried out according to ČSN ISO 719. Data of the extract from 2 g of crushed glass,
grain size between 300 and 500
+m, with water of degree of purity 2, for 60 min at 98 °C, are
used for practical purposes.
1.1.2. Resistance against water at 121°C
The test is carried out according to ČSN ISO 720. Data of the extract from 10 g of crushed glass,
grain size between 300 and 425
+m, with water of degree of purity 2, for 30 min at 121 °C, are
used for practical purposes.
1.1.3. Resistance against acids
SIMAX glass, same as all internationally approved borosilicate glasses, is practically resistant
against all aggressive agents except for hydrofluoric, fluorosilicic, phosphoric acids and hot con-
centrated lyes which markedly attack glass contact surfaces.
Glass surface is attacked by hydrofluoric acid even at low concentrations. Phosphoric acid and
lyes only slightly attack glass at low temperatures and concentrations. At high concentrations and
temperatures, glass resistance significantly decreases. Permanent alternation of acidic and alkaline
environment increases corrosion.
The test is carried out according to ISO 1776. Sample pieces, size 30–40 cm
, are subject to the
effect of an aqueous solution of hydrochloric acid at 100 °C for 3 hours.
1.1.4. Resistance against alkalis
The test is carried out according to ČSN ISO 695. Sample pieces, size 10–15 cm
, are submerged
in boiling solution of same volumes of sodium carbonate and sodium hydroxide for 3 hours.
1.2. Physical properties
The mean coefficient of linear thermal expansivity
(20 °C; 300 °C) 3.3
Transformational temperature T
525 °C
The glass temperature at viscosity of
in dPa.s 10
(the upper temperature of cooling) 560°C
The glass temperature at viscosity of
in dPa.s 10
(the temperature of softening) 825°C
The glass temperature at viscosity of
in dPa.s 10
(operation range) 1,260°C
The highest short-term allowed operation range 500°C
at 20°C 2.23 g
Elastic modulus E (Young's modulus ) 64
Poisson's constant
Heat-carrying capacity
(20 to 100°C) 1.2 W
1.2.1. Thermal properties
High resistance of products made of Simax glass against sudden changes in temperature - ther-
mal stability - depends on the low coefficient of linear thermal expansivity, relatively low module
tensile elasticity and relatively high thermal conductivity which result in a lower thermal gradient
in the product wall. When cooling and heating the glass product, no undesirable inner tension is
created. If a glass product is broken down as a result of changing the temperature, it is caused by
tensile stress on the product surface by linear expansivity of the glass at the time of quick cooling
from the product surface.
Permissible thermal stress depends on the temperature gradient in the glass part wall.
Provided that there is no temperature shock, the glass can be used up to temperatures of about
300°C. Generally and with respect to packing and jointing material, it is recommended to use the
glass piping and apparatus up to temperatures of about 200°C.
The boundary of possibility of quickly changing temperatures depends on thermal stress evoked
by process conditions, connection and fixing of parts, and is also influenced by the different wall
thickness of these parts. For these reasons, limiting value cannot be specified for all encountered
technological and process conditions.
A substantial condition of good resistance against temperature shock is the absence of mechani-
cal working and scratching of the uniform glass surface with coarse scratches or dull stains. Tem-
perature shock is a quick temperature change between the glass part and the environment. It
depends on the wall thickness of glass parts and the form of heating. Resistance of glass parts
against sudden changes in temperature in relation to the maximum part wall thickness according
to PN 13 8900.
Part size Wall thickness, mm Temperature difference, °C
DN 15–25 4 120
DN 40–100 5 100
DN 150–400 7 90
DN600 10 80
1.2.2. Heat transfer
Orientation values of total coefficient of heat transfer through SIMAX glass walls:
When used as a condenser (steam condensation around tubes, cooling water through tubes)
k = 290–580 W/m
K (250–500 kcal/m
h °C)
When used as an evaporator (water evaporation around tubes, steam condensation in tubes)
k = 465–814 W/m
K (400–700 kcal/m
h °C)
When used as a heat exchanger (heated liquid around tubes, heating liquid through tubes)
k = 250–400 W/m
K (200–350 kcal/m
h °C)
1.2.3. Change in length depending on temperature
The SIMAX glass features a very low coefficient of thermal expansivity.
Change in length of a piping line, length 100 m, in relation to temperature is given in the fol-
lowing table:
Temperature (°C) 50 100 150
Length change
¢ (mm) 17 33 50
In case of longer lines, the change in length of the piping due to change in temperature should
be taken into consideration and the piping should be fixed in a way that allows for the change
in length. This is usually achieved by using various expansion joints.
1.2.4. Mechanical properties
The mechanical properties and lifespan of products made of Simax glass depend partly on the
level of their finishing, especially as a whole, i.e. deep damage on the surface by handling and
subsequent thermal load deteriorates the lifespan.
Abrasion hardness of the glass matter 6° on the Mohs scale
Allowed tensile stress 3.5 MPa
Cooling Simax glass
Cooling is a thermal process with the purpose of preventing the generation of undesirable and
inadmissible high thermal stress in glass that would decrease the product resistance and/or re-
move any existing stress.
The cooling cycle involves three stages:
Temperature growth
(heating of the product) with the heating rate from feeding tempera-
ture to the upper cooling temperature.
for a certain period (lag, temper, stabilization) of products on the upper cool-
ing temperature, with the temperature differences in the product need to be balanced out,
including a decrease in the stress to a permissible limit.
Temperature decrease
(cooling and after-cooling) with the cooling rate from the upper to
the lower cooling temperature (this stage is important because permanent stress might
be generated) and from the lower cooling temperature to the final temperature or ambient
temperature (important for subsequent practical manipulation with the product).
1.2.5. Permissible stress with inner overpressure
Permissible inner overpressure in glass piping and equipment depends on nominal inner diam-
eter, shape, operating temperature, material of connecting parts, and type of gasket used.
In case of an apparatus assembled from parts of different inner diameters and shapes, the
permissible stress by inner overpressure is always given by the part of the lowest permissible
The operating values of liquid overpressure at a temperature difference between the inner and
outer wall
t = 5 °C (and temperatures up to 120°C) are:
DN 15 25 40 50 80 100 150 200 300 400 600
MPa 0.4 0.4 0.4 0.4 0.3 0.2 0.2 0.1 0.1 0.07 0.07
value in MPa = overpressure
Table of permissible overpressures for “T” pieces and crosses
* decreased value of permissible overpressure
The pressure shocks caused by running pumps or fittings should not exceed the maximum operat-
ing pressure of the piping, the piping must be protected (safety valves, receivers, etc.).
1.2.6. Permissible stress by inner underpressure
Permissible stress of the apparatus by vacuum depends on shape stability of large glass parts,
operating temperature, material of connecting parts and type of gasket used.
Long-term process experience has proven that an apparatus can be safely operated with the un-
derpressure corresponding to the absolute pressure of 0.0015–0.0020 MPa.
1.2.7. Optical properties
The SIMAX glass does not show any significant absorption in the visible spectrum and it is clear
and colourless. The permeability of ultraviolet rays is limited to middle-wave-length spectrum and
it is higher than for normal table glass, which allows the glass apparatus to be used for photo-
chemical reactions, e.g. sulfonation and halogenation processes.
1.2.8. Electrical properties
Under normal temperatures, Simax glass is a non-conductive material it is insulant. Specific re-
sistance in the environment resistant against humidity (20°C) above 10
– 10
cm. Permitivity
(20°C, 1 MHz) 4.6. Loss angle tg ¡
(20 °C, 1 MHz) 4.9
. Electrical losses rapidly increase
with increasing temperature and change with the frequency.
Wall thickness 1 mm
Wall thickness 2 mm
Wall thickness 5 mm
Wall thickness 9 mm
Wave length 9 mm
DN 80 100 150 200 300 400 600
25 0.3 0.2 0.2 0.1 0.1 0.07 0.07
40 0.3 0.2 0.2 0.1 0.1 0.07 0.07
50 0.3 0.2 0.2 0.1 0.1 0.07 0.07
80 0.2* 0.2 0.2 0.1 0.1 0.07 0.07
100 0.15* 0.15* 0.1 0.1 0.07 0.07
150 0.1* 0.07* 0.05* 0.05* 0.05*
200 0.07* 0.05* 0.05* 0.03*
. Layout and design of glass apparatus
The documentation of all steps of design preparation should contain the following items:
flow sheet
assembly diagram
building layout
requirements for building works
list of materials
technical report
safety regulations
3. Assembly of glass apparatus
Guarantees for correct and safe operation are only granted in the case that the assembly and commissioning
have been carried out professionally in accordance with the accompanying technical documentation and by
technicians who have been authorised to work with glass equipment (assembly men of the Kavalierglass or
individuals tested and approved by the Kavalierglass).
Assembly is to be carried out exclusively according to the contract documents approved by the customer. In
case the apparatus assembly is to be carried out in a way different from that specified by the documentation,
each such change should be approved in advance by the designer or the customer should write a record in
the assembly log book and make a change in the documentation.
Inspection of the building site before the assembly includes inspection of building preparedness of the
space intended for installing the apparatus and the space for assembly preparation. At the same time,
realization of the construction is inspected with respect to safety during assembly. Taking-over connect-
ing points applies particularly to technological piping to which the apparatus is to be connected and
on which the assembly depends.
Glass as well as non-glass parts are wrapped in disposable packing. Only non-damaged parts of equipment
can be assembled. Immediately before assembly, the glass parts should be cleaned to remove all impurities.
Fittings should be checked for conditions of seats, cones and all parts should be cleaned.
The assembly of supporting structures, fastening stirrups, supporting beds and frames is carried out accord-
ing to drawings and approved drawing documentation.
The assembly of parts is carried out by means of suitable mechanization tools in compliance with safety
regulations. When mounting vertical sections of glass apparatus, it is necessary to meet the condition of a
single firm support to prevent creating stress in glass parts. In case the whole weight of the apparatus can-
not be fixed to a single support it is necessary to use one fixed support and other sliding supports. The main
(fixed) support is to be fastened to a strength-appropriate glass part so that as much of the weight of the
apparatus as possible is fixed completely. None of movable parts of the seating may be seized or twisted.
Care should be taken to ensure that the assembly setting of movable parts of seating allows for the range
of dilatation movement during operation.
The apparatus should be sufficiently secured in stability by assembly elements so that forced assembly can-
not cause stress in glass parts. PTFE expansion joints are mounted so that they not only compensate dilata-
tions in the direction of the piping line axis but also prevent transferring vibrations.
After construction, reconstruction or repair and before commissioning, the assembled apparatus should
be tested. Individual types of tests are specified in the contract documents, namely:
check of assembled apparatus (constructional test) it is used for ascertaining that overall
realization and material used correspond to the submitted contract documents and agreed-upon
requirements of the customer, and preparedness for pressure test is checked
pressure tests they serve for verifying pressure resistance of the piping
test of temperature change it verifies behaviour of the piping during temperature fluctuations
tightness test it checks the glass piping for tightness.
A protocol is to be elaborated about the tests carried out.
5.1. Technical requirements
The operating conditions of each glass apparatus should be specified in the design. In case the process has
been designed by the customer using glass parts specified in design plans, leaflets and documentation of
the supplier, the limits of operating conditions cannot exceed the conditions specified for respective parts
by the manufacturer. Written operating instructions which describe in details the process sections, including
start-up, operation and termination of equipment operation, should be at disposal. Critical factors should
be specified which would result in stopping the operation. If this applies to working procedures in which
operating pressure limits can be exceeded, the glass apparatus should be protected at appropriate places
with pressure safety valves, piercing shutter fuses, alarm devices, etc. In chemical processes where a risk of
fire or explosion due to static electricity exists, the safety measures, particularly in processing and transport
of liquids in glass piping, should include earthing of a point on the external surface of each glass part. The
glass apparatus in which processing is carried out of chemical substances, the escape of which could result
in detriment to the operator's health, should be protected by a suitably fitted shield or by installing the whole
apparatus into a separate room which can be locked during operation.
5.2. Commissioning
Before putting the apparatus into operation, it is necessary to carry out a general inspection of all glass
parts for the possibility of occurrence of mechanical damage (impacts and cracks) incurred during
the assembly. These impacts and cracks could make performing glass apparatus testing impossible or
could cause material damages. During filling, heating-up and putting the apparatus into operation, the
glass stress cannot exceed the values considered by the designer according to valid regulations and
5.3. Maintenance of glass apparatus
5.3.1. Cleaning of glass
For cleaning the surfaces of glass parts and preserving all required properties of the glass, it is necessary
to clean parts immediately after shutting down the apparatus. No cleaning agent of abrasive character
may be used and chemical dissolving of impurities should be preferred. Because of a danger of gradual
loss in glass lustre and transparency of glass parts, cleaning agents of neutral reaction should be pre-
ferred to strongly alkaline ones.
5.3.2. Labour safety
During maintenance of the apparatus it is forbidden:
to work on an apparatus and equipment in operation and under pressure
to use glass parts of the apparatus as load-bearing parts
to hang auxiliary assembly tools on glass parts
to carry out a pressure test with a defective manometer or under pressure which is higher than the
prescribed value
dismantled parts should be cleaned and checked for possible damage
after repair it is necessary to inspect flange joints and the whole apparatus in operation for the period
of 24 hours
a record should be made in the revision book on each repair of the apparatus and test performed.
6. Guarantee
The manufacturer of the glass apparatus, the Kavalierglass, confirms that the product has been made
from SIMAX borosilicate glass 3.3 SIMAX, and that it meets the requirements of ČSN ISO 3585. The
dimensions and quality of workmanship of glass parts complies with the standards ČSN EN 1595, ČSN
EN 12 585 and the internal company standards. The manufacturer warrants for the period of one year
that no spontaneous failure of glass parts shall occur. Correct and safe operation is only covered by
the guarantee of the manufacturer if assembly and commissioning have been carried out profession-
ally in compliance with the technical documentation and by technicians who were trained for work-
ing with the glass apparatus supplied by the joint-stock company Kavalierglass (assembly men of the
Kavalierglass or persons tested and authorized by the experts of the joint-stock company Kavalierglass).
The manufacturer does not provide a guarantee in the case of mechanical damage and other failures
caused by improper storage, transport, non-professional assembly and cleaning, or by running the ap-
paratus beyond the parameters specified in the technical documentation. The products listed in the
documentation do not represent a binding production programme; the manufacturer reserves the right
to implementing technical modifications.