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We use the best available heat and chemical resistant
borosilicate glass of low alkali content for the manufacture of our glass apparatus,
properties of which are furnished below for your reference.
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Chemical
Properties Composition
A borosilicate glass having no elements of alkaline earth group and free from
arsenic, antimony and heavy metals.
Stability
Highly resistant to water and all acids with the exceptions of hydrofluoric acid
and hot glacial phosphoric. However, being predominantly a silicate, the glass is attacked
by caustic alkali to a measurable extent.
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Physical
Properties |
Linear coefficient of thermal expansion
32 x 10-7 / °C between 0 - 300 °C.
Thermal Conductivity
0.0027 cal/cm³/°C/Sec.
Specific Heat
0.20 cal/gm/°C.
Thermal Endurance
The glass can withstand a high degree of thermal shock, though the actual value
depends on the shape and dimensions of the article. A thin wall flask, for instance, can
withstand a sudden temprature reduction of 300 °C.
Temprature Limits in Service
Generally no part of the apparatus should be heated to a temprature exceeding
450°C, particularly for prolonged heating. When heated to above 300°C, it should be
allowed to cool slowly to avoid the possibility of leaving permanent stress in the glass.
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 Screw-thread tube attachment for hose connections
The usual method of
connecting water rubber hose to any glass part is by means of wetting the ends and by
using mechanical force to slide over the glass inlet or outlet and/or to remove the hose.
A superior method is employed for rubber hose connections, by incorporating a
screw-thread tube attachment as illustrated. This eliminates the risk of
breakage. |
USUAL
METHOD
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IMPROVED
METHOD
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Screwfilters with interchangeable filter discs (discs
have a glass rim) have the following features:
Long lasting interchangeable filter discs which are easy to clean
Safe and simple removal of filtrate
Economical and space-saving |
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Round Bottom Flasks, Four
Necks, All Necks Parallel |
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Flat Bottom Flasks, Four
Necks, All Necks Parallel |
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Buchner Filters, with
Domed Disc |
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Micro Filter Holder
Assembly, with Rubber Cork |
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Micro Filter Holder
Assembly with Ground Glass Joint |
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Screwcocks, High Vacuum,
Plain Bore, with VITON® Seal, Interchangeable Plunger |
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Tubes, Culture, Round
Bottom, with Bakelite Screw Cap and Rubber Liner |
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Tubes, Culture, Flat
bottom, with Bakelite Screw Cap and Rubber Liner, Ideal Replacement of Bijou Bottles,
McCartney Bottles and Universal Bottles |
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Despite a product range of over 2300 items we are
aware that some users may have specialised applications that require the use of
non-standard glassware.We are fully equipped to handle such requests and have tremendous
experience in meeting such requirements.We are therefore pleased to offer a specialised
glassblowing service to our valued customers, including but not limited to:
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Machining |
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Grinding |
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Joining/Shaping |
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Sintered glassware |
Please contact us to find out more about how Vensil can help
meet your requirements. |