Overview
EN ISO 4797:2015 (ISO 4797:2015) specifies an internationally accepted series of boiling flasks with conical ground joints for general laboratory use. Published by CEN/ISO, this third edition updates earlier versions and defines the types, materials, dimensions, joint sizes and marking requirements for conical (Erlenmeyer-style), flat‑bottom and round‑bottom boiling flasks used in chemical and analytical laboratories.
Key topics and technical requirements
- Types covered: conical flasks, flat‑bottom flasks and round‑bottom flasks with conical ground joints.
- Series of capacities: two alternative series (Series 1 and Series 2) differ in overall height and selection of joint sizes; manufacturers or national standards bodies typically choose one series.
- Material: flasks must be made from borosilicate glass 3.3 in accordance with ISO 3585 and be free of visible defects and internal stresses that impair performance.
- Dimensions: body diameters, wall thickness and nominal overall heights are specified (see ISO 1773 for dimension details); specific tables in the standard list nominal volumes, overall heights and recommended joint sizes.
- Ground glass joints: conical joints must comply with ISO 383, k6 series; joint sizes (e.g., 24/29, 29/32, 34/35, 45/40, 55/44) are defined per flask volume and series.
- Thermal shock endurance: flasks ≤ 3 000 ml must withstand a thermal shock endurance of 150 °C; flasks > 3 000 ml require 100 °C, tested per ISO 718.
- Marking: each flask must be permanently and legibly marked with nominal volume, joint size, manufacturer’s or vendor’s name/mark and an area suitable for pencil marking; referencing “ISO 4797” on the flask is recommended.
Practical applications and users
- Who uses this standard: laboratory glassware manufacturers, quality managers, procurement/specifiers, testing laboratories, university and industrial research labs, and standards committees.
- Typical uses: boiling, reflux and distillation assemblies, general heating in chemical synthesis, sample preparation and routine laboratory workflows requiring interchangeable conical joints.
- Benefits: ensures interchangeability, safety (thermal shock resistance), traceability and consistent fit with other standardized glassware (stoppers, condensers, adapters).
Related standards
- ISO 383 - Interchangeable conical ground joints
- ISO 718 - Thermal shock and thermal shock endurance - Test methods
- ISO 1773 - Narrow‑necked boiling flasks (dimensions)
- ISO 3585 - Borosilicate glass 3.3 - Properties
EN ISO 4797:2015 is essential for anyone specifying or producing standardized boiling flasks with conical ground joints to ensure compatibility, safety and conformity across international laboratory environments.
