Abstract
This specification covers a limit for thermal residual stress in reusable annealed glass laboratory apparatus as determined by prescribed photoelastic measurement procedures. This specification recognizes that photoelastic measurements are proportional to the difference of the principal stresses. The stress limit shall be measured and calculated to meet the specified requirements.
Scope
1.1 This specification covers a limit for thermal residual stress in reusable annealed glass laboratory apparatus as determined by prescribed photoelastic measurement procedures.
1.2 In broad classification, the laboratory glassware items covered by this specification, but not limited to, are:
beakers
Imhoff cones
bottles, aspirator
impingers
bottles, dropping
jars, battery
bottles, gas washing
jars, bell
bottles, infusion
jars, chromatography
bottles, milk test
jars, cylindrical
bottles, reagent
joints, ball and socket or standard taper
bottles, weighing
manometers
bulbs, absorption
percolators
bulbs, leveling
pycnometers
bulbs, sampling
stopcocks
burets
tubes, centrifuge
condensers
tubes, chromatography
crystallizing dishes
tubes, color comparison (turbidity)
culture dishes
tubes, combustion (ignition)
custom apparatus
tubes, connecting and adapter
cylinders, graduated
tubes, digestion
and plain
tubes, drying
desiccators
tubes, fermentation
extraction tubes
tubes, thistle (spray traps)
flasks
vapor traps
fritted ware
viscometers
funnels
watch glasses
generators, Kipp
grinder, tissue
1.3 This specification recognizes that photoelastic measurements are proportional to the difference of the principal stresses. The limit imposed represents a safety factor to cover a situation in which one of the principal stresses may be larger than the apparent stress.
1.4 This specification applies only to annealed glassware that is intended for sale as such. It excludes glassware that has been thermally tempered, ion-exchanged, or laminated with glass layers of differing expansion. The intent of this specification is to limit the residual stresses for safe consumer use in annealed glass, as it leaves the manufacturer.
1.5 Stresses introduced by thermal expansion differences within the glassware are covered by this specification. Graded and glass-to-metal seals are excluded.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
