BS EN ISO 24450:2005 pdf – Laboratory glassware — Wide-necked boiling flasks.
1 Scope This International Standard specifies requirements and dimensions for an internationally acceptable series of conical flasks and of flat-bottom and round-bottom flasks with wide neck for general laboratory purpose. The flasks are provided for ⎯ direct use in laboratory, fitting together with other equipment for general laboratory purposes; ⎯ further work up to other products. NOTE For narrow-necked boiling flasks, ISO 1773 applies. For boiling flasks with conical ground joints, see ISO 4797. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3585, Borosilicate glass 3.3 — Properties 3 Series and capacities 3.1 Series of nominal capacity The series of nominal capacities of wide-necked conical flasks is as follows (given in millilitres): 50 — 100 — 250 — 500 — 1 000 The series of nominal capacities of wide-necked round-bottom flasks is as follows (given in millilitres): 50 — 100 — 250 — 500 — 1 000 — 2 000 — 4 000 — 6 000 — 10 000 The series of nominal capacities of wide-necked flat-bottom flasks is as follows (given in millilitres): 50 — 100 — 250 — 500 — 1 000 — 2 000 3.2 Nominal capacity The nominal capacity of a flask is the value, selected from the series given in 3.1, which is closest to but not larger than the actual volume to the base of neck. NOTE The body dimensions recommended in Tables 1 and 2 take this requirement into account.
4 Material Flasks shall be made from borosilicate glass 3.3 in accordance with ISO 3585, and shall be free from visible defects which might affect performance, and free from any internal stress which would impair the performance of the flask. 5 Construction and dimensions 5.1 Construction 5.1.1 Stability Conical flasks and flat-bottom flasks shall stand vertically without rocking or spinning when placed on a level surface. 5.1.2 Neck The neck of the flask shall be substantially circular in cross-section and the mouth of the neck shall not be belled to any considerable distance from the top. The top of the neck shall be suitably strengthened. 5.2 Dimensions 5.2.1 Recommended dimensions Dimensions for wide-necked conical flasks are given in Table 1.
5.2.2 Neck length The length of the neck of conical flasks shall be 1 to 1,25 times the external diameter of the neck. 5.2.3 Dimensions of base The radius at the junction between the base and the side of conical flasks shall be between 15 % and 20 % of the maximum external diameter. The diameter of the base of flat-bottom flasks shall be approximately 50 % of the maximum external diameter. 5.2.4 Wall thickness Values for the wall thickness are given in Tables 1 and 2. Substantial local irregularities shall be avoided. Manufacturers shall take care that minimum wall thicknesses are compatible with safety requirements. 5.3 Graduation Wide-necked conical flasks may be provided with a scale approximately indicating the volume of liquid contained. 6 Marking The following inscriptions shall be permanently and legibly marked on all conical, flat-bottom and round- bottom flasks: a) the nominal volume of the flask, e.g. “100 ml”; b) the maker’s and/or vendor’s name and/or mark; c) each flask shall also bear an area with a surface suitable for marking with a pencil. It is recommended that reference is made on each flask to this International Standard, e.g. by the inscription “ISO 24450”.