Overview
EN ISO 6556:2012 - Laboratory glassware - Filter flasks is the CEN-adopted version of ISO 6556:2012. It specifies design, construction and testing requirements for filter flasks (conical or cylindrical) used for general laboratory filtration, particularly under vacuum. The standard limits material to borosilicate glass 3.3 and defines two series of flasks, dimensional limits, strength and marking requirements to ensure safety, interchangeability and durability.
Key topics and technical requirements
- Scope & material
- Applies to conical and cylindrical filter flasks for general laboratory use.
- Glass type: Borosilicate glass 3.3 (ISO 3585).
- Series and capacities
- Two series are defined:
- Series A: conical (100 ml, 250 ml, 500 ml, 1 000 ml, 2 000 ml) and cylindrical (3 L, 5 L, 10 L, 15 L, 20 L).
- Series B: conical with different vacuum-connection options (25 ml, 50 ml, 125 ml, 250 ml, 500 ml, 1 000 ml, 2 000 ml, 4 000 ml).
- Construction & dimensions
- Minimum wall thickness and base radius of curvature are specified to avoid weak points and ensure stable standing.
- Neck options: tapered/cylindrical or with interchangeable joint per ISO 383.
- Protective external plastic coating is permitted for mechanical protection.
- Vacuum connections
- Location and types differ by series. Options include tubular side-arms (tapered or corrugated), integral side-arms with glass threads, detachable side-arms and replaceable fittings.
- Strength & testing
- Pressure strength: must withstand an external-internal pressure differential of 2 bar (type test in Annex A - hydraulic external pressure for 1 min).
- Thermal shock endurance: type-tested to 75 °C per ISO 718.
- Marking
- Mandatory permanent markings: nominal capacity, maker/vendor name or mark, and glass type (unless indicated by maker’s mark).
Applications and typical users
- Practical uses:
- Vacuum filtration and sample preparation in chemical, biological and environmental laboratories.
- General laboratory filtration tasks requiring standardized, safe glassware.
- Typical users:
- Laboratory glassware manufacturers (design, quality control).
- Procurement and compliance teams specifying equipment for research, university and industrial labs.
- Laboratory managers and safety officers ensuring equipment matches standardized safety and testing criteria.
Related standards
- ISO 3585 - Borosilicate glass 3.3 (material properties)
- ISO 718 - Thermal shock and thermal shock endurance (test methods)
- ISO 383 - Interchangeable conical ground joints
Keywords: EN ISO 6556:2012, ISO 6556:2012, filter flasks, laboratory glassware, borosilicate glass 3.3, pressure strength, thermal shock endurance, vacuum connection.
